presentation1.pptx, radiological anatomy of the orbits, pns and petrous bone
TRANSCRIPT
Radiological imaging of the orbit PNS and petrous bone
Dr ABD ALLAH NAZEER MD
The orbit is a feature of the face and contains the globeGross anatomyIn the adult human the orbit has a volume of approximately 30ml of which the globe occupies 65ml It has a roof floor medial and lateral wall The orbit is open anteriorly where it is bound by the orbital septum which also contributes to the eyelids Posteriorly the orbit angles inward such that their apices communicate with the intracranial compartment via the optic canal and superior orbital fissureContents globe extraocular muscles cranial nerves optic nerve (CN II) branches of the oculomotor nerve (CN III) trochlear nerve (CN IV) ophthalmic division of the trigeminal nerve (CN Va)
abducents nerve (CN VI) autonomic nerves and gangliaciliary ganglionsympathetic root to the ciliary ganglion (parasympathetic root travels in the oculomotor nerve)
Arteriesophthalmic artery
Veinssuperior and ophthalmic vein
Fatlacrimal gland fascia bulbi (Tenons capsule)
Bony marginsThe orbits bony margins are made up of seven bonespars orbitalis of the frontal bonelacrimal bonelamina papyracea of the ethmoid boneorbital process of the zygomatic boneorbital surface of the maxillary boneorbital process of the palatine bonegreater and lesser wings of the sphenoid bone
CommunicationsThe orbit communicates posteriorly with the intracranial cavity via the optic canal through which the optic nerve and ophthalmic artery is transmitted Immediately inferolateral to the optic canal is the superior orbital fissur through which most neurovascular structures pass The infratemporal fossa is accessed via the inferior orbital fissure which is in direct continuation with the infraorbital foramen through which the infraorbital nerve exits to supply the skin below the eye (and where it is often damaged by a blow-out fracture)Medially small communications with the paranasal sinuses are via the anterior ethmoid foramen and posterior ethmoidal foramenAnteriorly the supraorbital notch is closed inferiorly by the orbital septum forming a fibrous supraorbital foramen The nasolacrimal duct drains the nasolacrimal sac via the nasolacrimal foramen
Normal orbit measurements
Orbital anatomy
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
The orbit is a feature of the face and contains the globeGross anatomyIn the adult human the orbit has a volume of approximately 30ml of which the globe occupies 65ml It has a roof floor medial and lateral wall The orbit is open anteriorly where it is bound by the orbital septum which also contributes to the eyelids Posteriorly the orbit angles inward such that their apices communicate with the intracranial compartment via the optic canal and superior orbital fissureContents globe extraocular muscles cranial nerves optic nerve (CN II) branches of the oculomotor nerve (CN III) trochlear nerve (CN IV) ophthalmic division of the trigeminal nerve (CN Va)
abducents nerve (CN VI) autonomic nerves and gangliaciliary ganglionsympathetic root to the ciliary ganglion (parasympathetic root travels in the oculomotor nerve)
Arteriesophthalmic artery
Veinssuperior and ophthalmic vein
Fatlacrimal gland fascia bulbi (Tenons capsule)
Bony marginsThe orbits bony margins are made up of seven bonespars orbitalis of the frontal bonelacrimal bonelamina papyracea of the ethmoid boneorbital process of the zygomatic boneorbital surface of the maxillary boneorbital process of the palatine bonegreater and lesser wings of the sphenoid bone
CommunicationsThe orbit communicates posteriorly with the intracranial cavity via the optic canal through which the optic nerve and ophthalmic artery is transmitted Immediately inferolateral to the optic canal is the superior orbital fissur through which most neurovascular structures pass The infratemporal fossa is accessed via the inferior orbital fissure which is in direct continuation with the infraorbital foramen through which the infraorbital nerve exits to supply the skin below the eye (and where it is often damaged by a blow-out fracture)Medially small communications with the paranasal sinuses are via the anterior ethmoid foramen and posterior ethmoidal foramenAnteriorly the supraorbital notch is closed inferiorly by the orbital septum forming a fibrous supraorbital foramen The nasolacrimal duct drains the nasolacrimal sac via the nasolacrimal foramen
Normal orbit measurements
Orbital anatomy
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Bony marginsThe orbits bony margins are made up of seven bonespars orbitalis of the frontal bonelacrimal bonelamina papyracea of the ethmoid boneorbital process of the zygomatic boneorbital surface of the maxillary boneorbital process of the palatine bonegreater and lesser wings of the sphenoid bone
CommunicationsThe orbit communicates posteriorly with the intracranial cavity via the optic canal through which the optic nerve and ophthalmic artery is transmitted Immediately inferolateral to the optic canal is the superior orbital fissur through which most neurovascular structures pass The infratemporal fossa is accessed via the inferior orbital fissure which is in direct continuation with the infraorbital foramen through which the infraorbital nerve exits to supply the skin below the eye (and where it is often damaged by a blow-out fracture)Medially small communications with the paranasal sinuses are via the anterior ethmoid foramen and posterior ethmoidal foramenAnteriorly the supraorbital notch is closed inferiorly by the orbital septum forming a fibrous supraorbital foramen The nasolacrimal duct drains the nasolacrimal sac via the nasolacrimal foramen
Normal orbit measurements
Orbital anatomy
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Normal orbit measurements
Orbital anatomy
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Orbital anatomy
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Gross anatomy
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Schematic showing positioning for a Waters projection (CM canthomeatal line CR central ray) B Radiograph of a Waters projection The petrous ridge lies below the maxillary sinus (a frontal sinus b medial orbital wall c innominate line d inferior orbital rim e orbital floor f maxillary antrum g superior orbital fissure h zygomatic-frontal suture i zygomatic arch)
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Schematic showing positioning for a Caldwell projection (CM canthomeatal line CR central ray) B Radiograph of a Caldwell projection The petrous ridge is positioned at the orbital floor Detail of the orbital floor and maxillary sinus is blocked C The radiograph is taken at a steeper angle so the petrous ridge is now positioned lower within the maxillary antrum (a frontal sinus b innominate line c inferior orbital rim d posterior orbital floor e superior orbital fissure f greater wing of sphenoidg ethmoid sinus h medial orbital wall i petrous ridge j zygomatic-frontal suture k foramen rotundum)
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Schematic showing positioning for a lateral projection (CR central ray) B Radiograph of a lateral projection (a orbital roof b frontal sinus c ethmoid sinus d anterior clinoid process e sella turcica f planum sphenoidale)
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Ultrasound anatomyAt the anterior pole of the eyeball the eyelids and the conjunctiva abutting the cornea produce a moderate echogenic structure which outlines the ventral part of the anterior chamber With high resolution transducers the cornea appears as a convex echofree thin line bounded posteriorly by an echogenic interface The anterior chamber is echofree and is delineated posteriorly by the strong reflecting line of the iris The pupil appears as a translucent disruption of iris continuity Posterior to it lies the anechoic lens The anterior margin of the lens is not apparent and neither is the posterior chamber which is too thin to be visible The lens diameter is 10 mm with a maximal thickness of 3-4 mm The posterior margin of variable spatial relationship with the ultrasonic beam is only partly apparent The ciliary body produces a focal thickening of the eye wall next to the margins of the lensThe vitreous humor is echofree homogenous and occupies more than two thirds of the eyeball volume Since it only adheres to the posterior wall in a few points movement of the vitreous humor relative to the wall can be observed during real time scanning The posterior wall of the eyeball is echogenic often with no inner layers With high frequency transducers and lowering of distal gain compensation the choroid appears less echogenic than neighboring retina or sclera
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Behind the eyeball the intraconal fat pad is hyperechoic mainly due to acoustic enhancement in the vitreous humor The optic nerve appears as a sagittal hypoechoic structure 4 5 ndash 5 mm thick than runs from the outer part of the eyeball to the tip of the orbit The length of the optic nerve is approximately 2 5 cm The extrinsic muscles that form the intraorbital muscular cone appear as hypoechoic bands with typical longitudinal striations The oblique muscles are almost never seen due to their close relation to the rectus muscles and thin belly The rectus muscles can always be assessed especially if trapezoid emission of ultrasound at the surface of the transducer is used They are oriented in a sagittal plane and occupy the four cardinal points in the orbit (superior inferior medial and lateral) The medial rectus muscle which is best seem has the maximal thickness of 4 mm The inferior rectus muscle is the most difficult to assess Normal orbital vessels (ophthalmic ciliary and retinal) are not seen on grayscale scans Color or power Doppler adjusted for low flow is the method of choice for vessel detection while spectral display is used to analyze flow velocity and patterns Typically central retinal and ciliary arteries display low resistance flowThe lachrymal glands occupy the upper outer angle of the anterior orbit They are almond shaped echogenic with the long axis below 1 cm Quite often they cannot be differentiated from neighboring fatty tissue
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
The anterior pole of the eye C = cornea P = pupil I = iris CB = ciliary body L = lens VH = vitreous humor
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
The retroocular space ON = optic nerve VH = vitreous humor
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Extrinsic eye muscles LRM = lateral rectus muscle MRM = medial rectus muscle
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Eyeball vessels CR = central retinal vessels ChB = choroid blush
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
The lachrymal gland (LG)
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W axial sectionwith fat suppression through midorbit showing LR- lateral rectus MR-medial rectus V-vitreous A -aqueous arrow - optic nerve arrow head-lens E-ethmoid sinus
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W axial section through the superior orbit showing the superior ophthalmic vein (arrow head) superior rectus (double arrows) In the same section lacrimal glands (single arrows) are well seen
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W axial section through the inferior orbit showing the inferior rectus (arrow head) inferior portion of the globe (G) ethmoid air cells (E) sphenoid sinus (S) cavernous sinus (white outlines 1 and 2) and flow void of internal carotid artery (arrow)
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W coronal section through the anterior orbit showing the globe (single arrow) lens (arrow head) and the inferior obique (double arrow)
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W coronal section through the globe showing the vitreous (V) lacrimal gland (L) medial rectus (arrow head) inferior rectus (single arrow) and superior rectus (double arrow)
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2W coronal section posterior to the globe showing the intraconal space (within the circle1) optic nerve () inferior rectus (short single arrow) medial rectus (arrow head) superior oblique (double arrow heads) superior rectus (double arrow) superior ophthalmic vein (long white arrow) lateral rectus (LR) T-turbinates and sinuses (E-ethmoid M-maxillary)
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
IO inferior oblique muscle IRGL global layer of inferior rectus muscle IROL orbital layer of inferior rectus muscle
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Radiology of Nasal Cavity and Paranasal Sinuses
Imaging modalities
X-RAYCTMRI
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Paranasal sinusesThe paranasal sinuses consists of usually four paired air-filled spaces named for the facial bones in which they are locatedmaxillary sinussphenoid sinusethmoid sinusfrontal sinusOsteomeatal complexNose and nasal cavity
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Occipito-Mental (OM) view - Normal
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Occipito-Mental 30ordm (OM30) view - Normal
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Computed tomography (CT) of the para-nasal sinuses (PNS)has nowadays become the investigation of choice for the radiological diagnosis of nasal and sinus diseases Unlike plain radiography sinus CT shows an excellent anatomical soft tissue and bony details helps in the diagnosis and gives detail of sinonasal anatomy for safe surgeryEndoscopic sinus surgery (ESS) is a common procedure which requires a meticulous assessment of patient and a detailed radiological description of the anatomy and its anatomical variations in nose and PNS Although the role of anatomical variations of osteomeatal complex in the etiology of sinonasal disease is controversial3 but knowledge of these variations in every patient is important before surgery is planned to avoid damage to surrounding vital structures like the orbit and the brain The frequency of these variations may differ among the different ethnic groups4 In review of literature there is no data on anatomical variations of nose and PNS in our population The aim of this study was to report the frequency of these variations in patients with sinonasal symptoms who underwent CT scan in the hospital
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Frontal Sinus
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Ethmoid Sinus
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Maxillary Sinus
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Sphenoid Sinus
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Petrous part of temporal boneThe petrous temporal bone (PTB) has a pyramidal shape with an apex and a base as well as three surfaces and angles apex
direct medially articulates with posterior aspect of the greater wing of sphenoid and basilar occiput forms internal border of the carotid canal and the posterolateral boundary of the foramen lacerum
basedirected laterally and fuses with the internal surface of squama temporalis and mastoid
The PTB has three surfaces - anterior posterior and inferior The anterior surface forms the posterior part of the middle cranial fossa It is continuous with the inner surface of the squamous part united by the petrosquamous suture Near its center lies the arcuate eminence which indicates the location of the superior semicircular canal Lateral to the arcuate eminence is a depression which indicates the position of middle ear cavity A shallow groove directed posterolaterally to open into the hiatus of the facial canal Lateral to this hiatus a smaller hiatus for the lesser petrosal nerve At the apex the termination of carotid canal is present
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
The posterior surface forms the anterior part of posterior cranial fossa It fuses with the inner surface of mastoid Near the center of the posterior surface is the internal acoustic meatus Posteriorly to the internal acoustic meatus is a small slit leading to the canal of the vestibular aqueductThe inferior surface forms part of the exterior of the base of the skull There are a number of foramina including the inferior opening of the carotid canal and posteriorly the jugular foramen and in between a small inferior tympanic canaliculus through which the tympanic branch of the glossopharyngealnerve passes The stylomastoid foramen is situated on the inferior surface It provides attachment to the levator veli palatini and the cartilaginous portion of the auditory tube
The petrous temporal bone has three anglessuperior angle - attachment of tentorium cerebelli its medial arm lodges the trigeminal nerve and the superior petrosal sinus lodges in the groove of
the angle posterior angle - contains a sulcus that lodges the inferior petrosal sinus medially and jugular notch of occipital bone forms the jugular
foramen laterally anterior angle - medial half articulates with the spinous process of the sphenoid and lateral half fuses with the squamous part by the petrosquamous suture
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Radiograph of the lateral view of temporal bone
1 posteroinferior limit of the middle cranial fossa
2 anterior limit of theposterior cranial fossi
3 internal auditory meatus 4 external auditory meatus 5 condylar neck 6 roof of glenoid fossa 7 articular tubercle 8 sigmoid notch of mandible 9 mastoid process 10 styloid process11 atlas
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Internal auditory meatus X-Ray
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
RADIO-IMAGING ANATOMY at 3TThe internal auditory canal- Has three parts the internal acoustic meatus (medial opening) the canal (an average of 8 mm) and the fundus of irregular shape (modulates the passage of the VII and VIII cranial nerves)- Nervous contents the facial nerve (the largest in size) and the cochleo-vestibular nerve that divides into the cochlear nerve and the vestibular nerve which further divides itself into the superior (innervates the utricle and the ampulla of the superior and lateral SCC) and the inferior branches (innervates the saccule and the ampulla of the posterior SCC)The singular nerve (or the posterior ampullary nerve) has its proper canal the singular canal in the postero-inferior quadrant of the fundus that can be often be observed with 3T imaging- Vascular content arterial by the labyrinthine artery and venous with three drainage pathways (internal auditory vein vein of cochlear aqueduct and vein of vestibular aqueduct)
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Axial section through the inner auditory canal (IAC) and the labyrinthe with visualization of the cochlear and inferior vestibular nerves The utricular macula is also well depicted
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Anterior coronal section through the IAC Outline of the facial nerve in itscomplete cisternal course the cohlear nerve is only partially viewed
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Posterior coronal section through the IAC Vestibular nervedivision and vestibular ganglion (of Scarpa) are visualized
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Appearance variant of the vestibular nerve with inferior vestibular division into the saccular nerve (that innerves the saccule) and the posterior ampullary nerve (for the ampulla of the posterior semicircular canal)
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Sagittal seriate sections of the IAC from medial (left) showing the pontocerebellarcistern to lateral (right) showing the fundus and inner ear structures
Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
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Cochlear nerve at the fundus of the IAC and its passage via the modiolus to the cochlea in an oblique sagittal section
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Heavily T2 coronal section respective to the IAC Vestibular and cochlearstructures are seen note the utricular macula and spiral lamina
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Sagittal section respective to the IAC through the inner ear in a 3D Heavily T2 sequence This section is also orthogonal to the macula
of the utricle and unfolds partially the cochlea
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Oblique coronal section through the anterior labyrinth and fundus of the IAC 3D Heavily T2 sequence
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
FLAIR sequence in the axial plane four hours after Gd intravenous injection the saccule and part of the utricle are visualized
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Axial FLAIR Gd sequence through the utricle the saccule is partially visualized
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Heavily T2 in the plane of the lateral semicircular canal (oblique axial) The ampulla and its ampullary crest (low signal) are seen
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
FLAIR Gd sequence section in the lateral SCC plane passing through the utricle
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Section in the plane of the superior semicircular canal (plane of Poumlschl sagittal to the petrous bone) with heavily T2 sequence
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Section in the same plane (as Fig14) of the superior semicircular canal with FLAIR Gd sequence
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
T2 sequence in the plane of the posterior SCC (plane of Stenver coronal to the petrous bone) Notice the common part of the superior and posterior semicircular canals ie the common crus
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
FLAIR and Heavily T2 sequences sections in the coronal plane Notice theposition of the utricular macula (T2 sequence) relative to the utricle (FLAIR)
Thank You
Thank You