atlas on x-ray and angiographic anatomy, 1e (2013) [unitedvrg]

Atlas on X-ray and Angiographic Anatomy


JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTDNew Delhi • London • Philadelphia • Panama

Hariqbal Singh MD DMRDProfessor and Head

Department of Radiology Shrimati Kashibai Navale Medical College

Pune, Maharashtra, India

Parvez Sheik MBBS DMREConsultant Radiology

Shrimati Kashibai Navale Medical CollegePune, Maharashtra, India

®

Jaypee Brothers Medical Publishers (P) Ltd.

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First Edition: 2013

ISBN 978-93-5090-432-9

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Dedicated toOur dear consortsArvind Hariqbal

andNaasiya Musthafa

SayingAnatomy is a nursery

offers framework to enter the infirmary, clasp it firmly

it will help analyze the pathology rightly with foundation in place

all is well the value of radiology cannot be measured

it can only be treasured.

–Hariqbal Singh

Preface

Human anatomy has not transformed over the years but the advance in imaging has changed the perception of structural details. Thorough understanding of the normal anatomy is an essential prerequisite to precise diagnosis of pathology. Atlas on X-ray and Angiographic Anatomy is loaded with meticulously labeled illustrations. This book is steal a look into the anatomy in an easy and understandable manner. This atlas is meant for undergraduates, residents in orthopedics and radiology, orthopedic surgeons, radiologists, general practitioners and other specialists. It is meant for medical colleges, institutional and departmental libraries and for stand-alone X-ray and orthopedic establishments. They will find the book useful.

Hariqbal Singh Parvez Sheik

Acknowledgments

We thank Professor MN Navale, Founder President, Sinhgad Technical Educational Society and Dr Arvind V Bhore, Dean, Shrimati Kashibai Navale Medical College, Pune, Maharashtra, India, for their kind acquiescence in this endeavor. Our special thanks to the consultants Dr Sasane Amol, Roshan Lodha, Santosh Konde, Shishir Zargad, Yasmeen Khan, Shivrudra Shette, Anand Kamat, Varsha Rangankar, Prashant Naik, Abhijit Pawar, Aditi Dongre, Rajlaxmi Sharma, Manisha Hadgaonkar, Subodh Laul, Sumeet Patrikar, Ronaklaxmi, Shrikant Nagare and Vikash Ojha, who have helped in congregation of this imagery and for their indisputable help in assembly of this educational entity. Our special appreciation to the technicians Mritunjoy Srivastava, Premswarup, Sudhir Mane, Sonawane Adinath, Deepak Shinde, Vinod Shinde, Yogesh Kulkarni, Pravin Adlinge, Parameshwar and Amit Nalawade, for their untiring help in retrieving the data. Our gratitude to Sachin Babar, Anna Bansode, Sunanda Jangalagi and Shankar Gopale, for their clerical help. We are grateful to God and mankind who have allowed us to have this wonderful experience. Last but not least, we would like to thank M/s Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India, who took keen interest in publishing the book.

Contents

1. Skull 1

2. Spine 13

3. X- ray Chest 28

4. Abdominal Radiograph 34

5. Upper Limb 37

6. Lower Limb 49

7. Angiograms 67

8. Radiological Procedures 103

9. OssificationCenters 127

10. ProductionofX-rays 133

11. DigitalSubtractionAngiography 135

12. Computed and Digital Radiography 137

13. PictureArchivingandCommunicationsSystem 140

14. Computed Tomography Contrast Media 142

Index 145

INTRODUCTION

The term ‘Skull’ includes the mandible, likewise the term ‘Cranium’ is the ‘Skull’ without the mandible (Figs 1.1 and 1.2). The cranial cavity has a roof (cranial vault) and floor (base of the skull). The frontal bone occupies the upper third of the anterior view of the skull; the rest is formed by the maxillae and mandible. The frontal bone extends downwards to form the upper margins of the orbits. Medially the frontal bone articulates with the frontal process of each maxilla. Laterally the frontal bone projects as the zygomatic process to make the frontozygomatic suture with the zygomatic bone at the lateral margin of orbit (Figs 1.3 to 1.6). The frontal bone articulates with the parietal bones at the coronal sutures (which run transversely). The temporal bone consists of five parts– Squamous, mastoid, petrous, tympanic and styloid process. The squamous portion forms part of wall of temporal fossa and gives rise to zygomatic process. The mastoid portion contains the mastoid antrum, in adults it elongates into mastoid process. The mastoid antrum communicates with the remainder of mastoid air cells and with the epitympanum via the aditus ad antrum. The petrous portion is wedge-shaped and lies between the sphenoid bone anteriorly and occipital bone posteriorly. The tympanic portion lies below the squamous part and in front of the

mastoid process. The styloid portion forms the styloid process. The temporal fossa is the area bounded by the superior temporal line, zygomatic arch and the frontal process of the zygomatic bone. The zygomatic arch is formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. The zygomatic process of the maxilla articulates with the zygomatic bone. The zygomatic bone forms the bony prominence of the cheek (Figs 1.7 to 1.10). The styloid process is a part of the temporal bone, from its tip the stylohyoid ligament passes to the lesser horn of hyoid bone. At the base of the skull medial to the styloid process the petrous bone is deeply hollowed out to form the jugular fossa with an opening called as jugular foramen through which the internal jugular vein passes. Anterior to the jugular foramen the petrous part of the temporal bone is perforated by the carotid canal, allows the internal carotid artery to pass through it (Fig. 1.11). Between the basiocciput and the body of sphenoid bone lies the foramen lacerum, it allows the small emissary vein and meningeal branch of ascending pharyngeal artery to pass through it. The roof of the infratemporal fossa is pierced medially by the foramen ovale, through which passes the mandibular nerve, lesser petrosal nerve, accessory meningeal artery and emissary veins. The base of the spine of sphenoid is perforated by the foramen spinosum

SkullC H A P T E R

1

Atlas on X-ray and Angiographic Anatomy2

Figs 1.1A to D: CT scan multiplanar reconstruction images of skull: (A) Frontal view; (B) View from back; (C) Lateral view; (D) View from below

which allows the middle meningeal vessels to pass through it. The stylomastoid foramen lies behind the base of styloid process. Medial to the third molar tooth on either side is the greater palatine, foramen between the horizontal plate

of palatine bone and the palatine process of the maxilla, the greater palatine vessels and nerves pass through it. Behind the greater palatine, there are numerous small openings called the lesser palatine foramina in the pyramidal process of

A B

C D

Skull 3

Figs 1.2A and B: X-ray skull—AP view

A

B


Figs 1.3A and B: X-ray skull—Lateral view

A

B

Skull 5

Fig. 1.4: X-ray skull—Mastoid view (Schuller’s view)

Fig. 1.5: X-ray skull—Lateral view (close-up view to show the pituitary fossa)

palatine bone through which the lesser palatine vessels and nerves pass. There are two parietal bones on either side of skull. They are seen better on lateral views of skull and they articulate with the frontal bone anteriorly at the coronal sutures. Posteriorly, the parietal bones articulate with occipital bone and temporal

bone mastoid process at lambdoid suture. The bregma is the area in midline where the coronal sutures and the two parietal bones meet. Behind the bregma, the parietal bones articulate in the midline sagittal suture. This midline sagittal suture ends at the lambda in posteriorly. The lambda is the area posterior where the sagittal suture ends


Fig. 1.6: X-ray skull—PA view (Caldwell view for paranasal sinuses)

Fig. 1.7: X-ray skull—Water’s view (for paranasal sinuses)

Skull 7

Fig. 1.8: X-ray skull—Reverse Water’s view

Fig. 1.9: X-ray skull—Towne’s view (30o fronto-occipital view)


Fig. 1.10: X-ray skull—Submentovertical view

Fig. 1.11: X-ray skull showing base of skull

Skull 9

in midline and the apex of occipital bone reaches out to join it in midline. The mastoid region of the temporal bone articulates with the parietal and occipital bones posteriorly, the mastoid process projects down at the sides. Inferiorly the parietal bones articulate with the squamous portion of temporal bone on either side. The occipital bone on its lower surface has a ridge which is pointing towards the base of the mastoid process; this is called the external occipital protuberance. The basiocciput extends forward from the foramen magnum and fuses with the basis phenoid. The foramen magnum is located in the basilar part of the occipital bone (basiocciput). The pharyngeal tubercle is a slight bony prominence in front of the foramen magnum. One-third of the foramen magnum lies in front and two-thirds behind an imaginary line joining the tips of the mastoid processes. This is contrary to the occipital condyles, where two-thirds of the condyles lie in front of this imaginary line. The internal surface of the base of skull is divided into the anterior, middle and posterior cranial fossa. The orbital part of the frontal bone forms a large part of anterior cranial fossa. The anterior cranial fossa extends up to the posterior edge of the lesser wing of sphenoid. The anterior cranial fossa articulates with the cribriform plate medially. The crista galli is a sharp projection of the cribriform plate. The sphenoid bone contributes to the middle cranial fossa. The small midline body of sphenoid bone contains the sella turcica (means ‘Turkish saddle’), a small elevation in front of sella turcica is called tuberculum sellae (Fig. 1.5). The tuberculum sellae has three small spikes, the middle spike is called the middle clinoid process, the two lateral spikes are called anterior clinoid process. At the posterior edge of the sella turcica is an elevation called the dorsum sellae, which has two lateral spikes called the posterior clinoid process. A fibrous portion of the dura forms the roof of the sella turcica extending from

the tuberculum sellae to the dorsum sellae and is called the diaphragm sellae. The diaphragm sellae has a central opening to allow the pituitary stalk and vessels to pass through it. The posterior cranial fossa extends from the petrous temporal bone anteriorly to the internal occipital protuberance in the midline. The floor is formed by the foramen magnum, basiocciput and posterior part of sphenoid bone. The dorsum sellae slopes downwards in front of foramen magnum, this slope is called the clivus. The mandible or the jaw bone is a U–shaped, a horizontal central part with two lateral ramus on each side. The posterior border of each ramus has a condyle with a neck which articulates with the temporal bone forming the temporomandibular joint, while the anterior border of each ramus is sharp and is called the coronoid process (Figs 1.1 to 1.4). The temporormandibular joint is a synovial joint between the head (condyle) of the mandible and mandibular fossa on the undersurface of the squamous part of the temporal bone. The joint is separated into the upper and lower cavities by a fibrocartilaginous disc within it. There is no hyaline cartilage within the joint which makes it an atypical synovial joint. The synovial membrane lines the inside of the capsule and the intracapsular posterior aspect of the neck of the mandible. The articular disc is attached around its periphery to the inside of the capsule and to the medial and lateral poles of the head of the mandible. The joint is more stable with the teeth in occlusion than when the jaw is open. The movements at the temporomandibular joint are depression and elevation (opening and closing of the jaws), side to side grinding movements, retraction and protaction movements (retrusion and protrusion).

THE NASAL CAVITY AND NASAL SEPTUM

The nasal cavity is pear-shaped, broader below and narrower at the top. From its lateral walls the


conchae project into the nasal cavity. There are three conchae—Superior, middle and inferior conchae. The superior concha is small and is found high in nasal cavity, its lower edge overlies the superior meatus. The sphenoethmoidal recess lies above and behind the superior concha and receives the ostia of sphenoidal sinus. The middle concha lies between the superior and inferior concha. The area in front of the middle meatus is the atrium of nose. Posteriorly, the middle meatus is related to the splenopalatine foramen. The inferior concha lies below the middle concha articulates anteriorly with the maxilla and posteriorly with the palatine bone. The nasal septum (Fig. 1.12) is normally in the midline, it consists of bone (vomer) and cartilage. It has a lower free margin, superiorly it articulates with the medial ends of frontal bone and also the frontal process of maxilla. The two maxillae on either side meet in the midline and project forwards as the anterior nasal spine at the lower margin of the nasal aperture. The vomer articulates with the sphenoid body and forms the posterior border of the septum. The septal cartilage forms the anterosuperior part of the septum. The floor of the nose is formed by the upper surface of the hard palate. The central part of the roof of nose is the cribriform plate of the ethmoid.

THE PARANASAL SINUSES

The paranasal sinuses all arise as evaginations from the nasal fossa. It comprises of frontal sinuses, maxillary sinuses, sphenoid sinuses and ethmoidal sinuses. The nasal cavity contains the superior meatus, middle meatus and the inferior meatus. The superior meatus drains the posterior ethmoidal air cells and sphenoidal sinuses. The middle meatus drains the frontal sinuses, maxillary sinuses and anterior ethmoidal air cells. The osteomeatal complex comprises of the uncinate process, ethmoid infundibulum, maxillary sinus ostium, middle turbinate, frontal recess and ethmoid bulla. The inferior meatus has opening for the nasolacrimal duct (Figs 1.8 to 1.12).

The maxillary sinus lies in the body of maxilla, the sinus is triangular in shape, the apex in the zygomatic process of maxilla and the base towards the lateral wall of the nose. The roof of the sinus is the floor of the orbit. The floor of the sinus is formed by the alveolar part of maxilla. The infratemporal fossa and pterygopalatine fossa lies behind the posterior wall of maxillary sinus. The ostium of maxillary sinus is on the superomedial aspect of the sinus and opens into the middle meatus on the same side into the nasal cavity (Figs 1.2B and 1.3B). The ethmoidal sinus lies between the nasal cavity and orbit. The sinus is divided by multiple thin bony septa into the anterior and posterior group of ethmoidal air cells. The lateral wall of the ethmoidal sinus forms a part of the medial wall of orbit; it is paper thin and is called the lamina papyracea. The ostia of anterior ethmoidal air cells drain into the middle meatus. The ostia of posterior ethmoidal air cells drain into the superior meatus. The sphenoidal sinus occupies the body of sphenoid bone. A vertical septum divides the cavity into two unequal halves. The roof of sphenoid sinus is formed by pituitary fossa and middle cranial fossa. Laterally the sphenoid sinus is related to the cavernous sinus and internal carotid artery. Posteriorly, the sphenoid sinus is related to the posterior cranial fossa and pons. The ostium of sphenoidal sinus is in the anterior wall of the sinus and opens into the superior meatus or into the sphenoethmoidal recess. The frontal sinuses are formed within the frontal bone on either side near midline. Its floor forms the roof of orbit medially. Posteriorly the frontal sinus is related to anterior cranial fossa. The ostium of frontal sinus is at its lower medial edge and drains into the middle meatus in nasal cavity or in some cases into the anterior ethmoidal air cells.

THE ORBIT

The bony orbit is a cavity, shaped like a pyramid with its apex posteriorly and the base forming

Skull 11

Fig. 1.12: X-ray skull—Lateral view (for nasal bones)

Fig. 1.13: X-ray skull—AP view in a 2-year-old child

the orbital margins anteriorly. The orbital roof is formed by the frontal bone, which separates the orbit from the anterior cranial fossa. The orbital floor is formed by the orbital plate of the maxilla,

portions of the palatine bone and the zygoma (Figs 1.10, 1.13 and 1.14). The maxillary portion of orbital floor is usually involved in blow out fractures. The medial orbital wall is the thinnest


Fig. 1.14: X-ray skull—Lateral view in a 2-year-old child

of all the orbital walls and comprises of frontal process of the maxilla, lacrimal bone, lamina papyracea and bony sphenoid. The lateral wall of orbit is formed by the zygoma and greater wing of sphenoid. The superior orbital fissure is a space between the greater and lesser wings of sphenoid. The inferior orbital fissure is formed by the maxilla, the palatine bone and the greater wing of sphenoid. The optic canal lies within the lesser wing of sphenoid, the optic nerve and ophthalmic artery encased in the dural sheath pass through it.

Structures passing through the superior orbital fissure: Superior ophthalmic vein, the rectus muscles (superior, inferior, medial and lateral), lacrimal nerve, frontal nerve, trochlear nerve, oculomotor nerve, abducent nerve, nasociliary nerve. Structures passing through the inferior orbital fissure: Infraorbital artery, inferior ophthalmic vein, zygomatic nerve, infraorbital nerve. Structures passing through the optic canal: Optic nerve, ophthalmic artery.

SpineC H A P T E R

2

Two common radiographic views taken for the spine are the AP view and the lateral view. Most disease process involving the vertebral body or the posterior elements can be noted on these views, however, special views like posterior oblique view may be necessary in some cases. The spine is made up of five groups of vertebrae. The portion of spine around the neck region is cervical spine. It is formed by first seven vertebrae which are referred as C1 to C7, followed by 12 thoracic vertebrae referred as T1 to T12 and subsequently five lumbar vertebrae L1 to L5 in the low back area. The sacrum is a big triangular bone at the base, its broad upper part joins the L5 vertebra and its narrow lower part joins the coccyx or tail bone.

CERVICAL SPINE

It starts with first cervical vertebra (C1) attached to the bottom of the skull, the basiocciput. Atlas is the name given to C1 vertebra as it supports and balances the weight of the skull. It has practically no body or spinous process, it appears as two thickened bony arches which join anteriorly as anterior tubercle and posteriorly as posterior tubercle. These two thickened bony arches join to form a large hole with two transverse processes. On its upper surface, the atlas has two facets

that unite with the occipital condyles of the skull. Structure of atlas is unique and has a large opening which accommodates spinal cord (Figs 2.1 and 2.2). The second vertebra is the “axis”, it lies directly beneath the atlas vertebra. It bears large bony tooth-like protrusion on its summit, the odontoid process or the dens. This process projects upward and lies in the ring of the atlas. The joints of the axis give the neck its ability to turn from side to side, i.e. left and right, as the head is turned, the atlas pivots around the odontoid process. The odontoid process arises from anterior part of C2 vertebrae and articulates with the C1 vertebrae above to form the atlanto-occipital joint (Figs 2.2, 2.3 and 2.10). Special views may be taken on plain radiographs to demonstrate the atlantoaxial joint and atlanto-occipital joint. The transverse processes of the cervical vertebrae have large transverse foramina to allow the vertebral arteries into the cranium. The spinous processes of the second to fifth cervical vertebrae are forked providing attachments for various muscles. C3-C6 vertebrae have a typical structure. C7 vertebra is called vertebra prominens because of a long prominent thick nearly horizontal not bifurcated spinous process which is palpable from the skin (Figs 2.4 to 2.9).


Figs 2.1A to D: (A) Cervical spine MRI sagittal section T2WI; (B) Multiplanar reconstructed CT scan images of cervical spine posterior view; (C) View from above; (D) Lateral view

A B C D

There are eight cervical spinal nerves and the neural foramina of cervical spine allow the cervical spinal nerves to exit out of the spinal canal.

DORSOLUMBAR SPINE

It consists of twelve vertebrae in the chest area, the first thoracic vertebra articulates with the C7 vertebra above and the last thoracic vertebra articulates with the first lumbar vertebra below. The thoracic vertebrae are larger in size than those in the cervical region. They have long, pointed spinous processes that slope downward, and have facets on the sides of their bodies that join with ribs. From the third thoracic vertebra onwards to the last thoracic vertebra, the bodies of these bones increases in size gradually (Figs 2.11 to 2.13). This reflects the stress placed on them by the increasing amounts of body weight they bear. There are five “lumbar vertebrae” in the

lower back. They have larger and stronger bodies to provide support. The transverse processes of these vertebrae project backward at sharp angles, while their short, thick spinous processes are directed nearly horizontally.

LUMBOSACRAL SPINE

The 5 lumbar vertebrae in the lower back are prone to injuries. On AP views the pedicles and transverse process need to be examined to rule out any fracture. On lateral views, the curvature of lumbar spine needs to be examined, note any slipping of one lumbar vertebra over the other. The intervertebral disc spaces should be equal in size (Figs 2.14 to 2.16). Additional views like posterior oblique view may be necessary in some cases. The sacrum is a large triangular bone on AP view at the base of the lower spine. Its broad upper part joins the lowest lumbar vertebrae and its narrow lower part joins the coccyx or “tail

Spine 15

A

B

Figs 2.2A and B: X-ray cervical spine—Lateral view


Fig. 2.3: X-ray cervical spine—Lateral view for C1-C2 vertebrae

bone” (Fig. 2.17). The sides are connected to the iliac bones (the largest bones forming the pelvis). The sacrum is a strong bone and rarely fractures. The five vertebrae that make up the sacrum are separate in early life, but gradually become fused between the eighteenth and thirtieth years. The spinous processes of these fused bones are represented by a ridge of tubercles. The weight of the body is transmitted to the legs through the pelvic girdle at these joints.

COCCYX

It is the lowest part of the vertebral column and is attached by ligaments to the margins of the sacral hiatus. It is better viewed on lateral views of sacrum with coccyx (Fig. 2.17). Sometimes bowel gases may obscure a clear picture of coccyx. When a person is sitting, pressure is exerted on the coccyx, and it moves forward, acting like a shock absorber. Sitting down with force may cause the coccyx to be fractured or dislocated.

GENERAL FEATURES OF SPINE

The vertebral body is shaped like an hourglass, thinner in the center with thicker ends. Outer cortical bone extends above and below the

superior and inferior ends of the vertebrae to form rims. The superior and inferior endplates are contained within these rims of bone. The bodies of adjacent vertebrae are joined on the front surfaces by “anterior ligaments” and on the back by “posterior ligaments”. A longitudinal row of the bodies supports the weight of the head and trunk. Intervertebral discs are found between each vertebra. They are better viewed on lateral radio-graphs. Intervertebral discs make up about one-third of the length of the spine and constitute the largest organ in the body without its own blood supply. The discs receive their blood supply through movement. The discs are flat, round structures about a quarter to three quarters of an inch thick with tough outer rings of tissue called the annulus fibrosis that contain a soft, white, jelly-like center called the nucleus pulposus. Flat, circular plates of cartilage connect to the vertebrae above and below each disc. Intervertebral discs separate the vertebrae, and act as shock absorbers for the spine. Projecting from the back of each body of the vertebra are two short rounded stalks called “pedicles”. They form the sides of the “vertebral foramen”. They can be viewed on both AP and

Spine 17

Figs 2.4A and B: X-ray cervical spine—AP view

A

B


Fig. 2.5: X-ray cervicothoracic junction—AP view

Fig. 2.6: X-ray cervical spine swimmer’s view for cervicothoracic junction

lateral radiographs. Pedicles extend posteriorly from the lateral margin of the dorsal surface of the vertebral body. The laminae are two flattened plates of bone extending medially from the pedicles to form

the posterior wall of the vertebral foramen. These laminae are better seen on lateral views on radiographs. They fuse posteriorly in the midline to become spinous process. The pars interarticularis is a special region of the lamina

Spine 19

Fig. 2.7: X-ray cervical spine right posterior oblique for intervertebral foramina

Fig. 2.8: X-ray cervical spine—Lateral view in flexion


Fig. 2.9: X-ray cervical spine—Lateral view in extension

Fig. 2.10: X-ray cervical spine open mouth view for atlantoaxial junction

between the superior and inferior articular processes. A fracture or congenital anomaly of the pars may result in a spondylolisthesis. The pedicles, laminae, and spinous process together complete a bony vertebral arch around the vertebral opening, through which the spinal cord passes. Between the pedicles and laminae

of a typical vertebra is a “transverse process” that projects laterally and toward the back. Various ligaments and muscles are attached to the transverse process. Projecting upward and downward from each vertebral arch are “superior” and “inferior” arti culating processes. These processes bear cartilage-covered facets by

Spine 21

Figs 2.11A to C: Multiplanar reconstructed CT scan images of dorsolumbar spine: (A) Posterior view; (B) Anterior view; (C) Lateral view

A B C

which each vertebra is joined to the one above and the one below it. These facet joints facilitate smooth gliding movement of one vertebra on another to produce twisting motions and rotation of the spine. Facet joints are also called as zygapophyseal joints. On the surfaces of the vertebral pedicles are notches that align to create openings, called “intervertebral foramina”. These openings provide passageways for spinal nerves that exit out of the spinal cord.

SPINAL CANAL AND SPINAL CORD

The spinal canal is bounded anteriorly by the vertebral bodies, the intervertebral discs,

posterior longitudinal ligament. Posteriorly it is related to the lamina and ligamentum flavum. Laterally on either side, it is related to the pedicles. The intervertebral foramina contain the spinal nerves, posterior root ganglia, spinal arteries and veins. The vertebral canal contains the spinal cord. The spinal canal encases the spinal cord. The bones and ligaments of the spinal column are aligned in such a manner to create a column that provides protection and support for the spinal cord. The outermost layer that surrounds the spinal cord is the dura mater, which is a tough membrane that encloses the spinal cord and prevents cerebrospinal fluid from leaking out. The space between the dura and the spinal canal is called the epidural space. This


Figs 2.12A and B: X-ray dorsolumbar spine—Lateral view

A

B

Spine 23

Figs 2.13A and B: X-ray dorsolumbar spine—AP view

A

B

space is filled with tissue, vessels and large veins. Up to the third month of fetal life, the spinal cord is about the same length as the canal. The growth of the canal outpaces that of the cord from the 3rd month onwards. In an adult the lower end of the spinal cord usually ends at approximately the first lumbar vertebra, where it divides into many

individual nerve roots that travel to the lower body and legs. This collection of group of nerve roots is called the “cauda equina”. MRI spine is the modality of choice to examine the spinal canal and spinal cord. CT spine is preferred in cases of acute trauma and those who cannot undergo MRI studies.


Figs 2.14A to D: Multiplanar reconstruction CT scan images of lumbosacral spine: (A) Posterior view; (B) Lateral view; (C) Lateral view showing the intervertebral neural foramina; (D) Oblique view

A B

C

D

SOME DIFFERENTIATING FEATURES BETWEEN CERVICAL, THORACIC AND LUMBAR VERTEBRAE

C3-C6 vertebrae have atypical features. The body of these four vertebrae is small and broader from side-to-side than from front-to-back. The pedicles are directed laterally and backward. The laminae are narrow, and thinner above than below. The vertebral foramen is large and has triangular shape. The spinous process is short and bifid. Superior articular facets face backward, upward, and slightly medially and inferior face forward, downward, and slightly laterally. The foramen transversarium is an opening in the transverse processes of the seven cervical verte brae. It gives passage to the vertebral artery, vein and plexus of sympathetic nerves in each of the vertebrae except the seventh, which lacks the artery. C7 has enlarged spinous process called the vertebral prominence.

The thoracic vertebrae have costal facets for ribs on either sides of the vertebral body. They increase in size gradually from T3 vertebra downwards. The lumbar vertebrae have neither a foramen in transverse process nor costal facets; they are larger than the dorsal and cervical vertebrae in size.

RADIOLOGICAL IMPORTANCE OF VERTEBRAL COLUMN IN SPINAL INJURIES

The vertebral column can be sub divided as anterior column, middle column and the posterior column. Injuries involving the middle and posterior columns result in unstable injuries.• Anteriorcolumnis formedbyanterior longi

tudinal ligament, anterior annulus fibrosus and anterior part of vertebral body.

• Middlecolumn is formedbyposterior longitudinal ligament, posterior annulus fibrosus and posterior part of vertebral body.

Spine 25

Figs 2.15A and B: Lumbosacral spine X-ray—AP view

A

B


Figs 2.16A and B: Lumbosacral spine X-ray—Lateral view

A

B

Spine 27

Fig. 2.17: Sacrum and coccyx X-ray—Lateral view

• Posteriorcolumnincludesposteriorelementsand ligaments.

RADIOLOGICAL IMPORTANCE OF CRANIOVERTEBRAL JUNC TION

Chamberlain line is the line between posterior part of hard palate and posterior margin of

foramen magnum. Normally the tip of odontoid process lies at or below this line. Basilar line is the line along the clivus and it usually falls tangent to the posterior aspect of the tip of odontoid. Craniovertebral angle (Clivus-canal angle) is angle between basilar line and a line along posterior aspect of odontoid process. If this angle is < 150º, cord compression can occur on the ventral aspect.

When viewing the chest X-ray, check first for the technical factors:• ProjectionAPorPAview,etc.• Orientation(rightorleft)• Rotation• Penetration• Degreeofinspiration. On posteroanterior (PA) view, the X-raybeamfirst enters the patient from the back andthen passes through the patient to the film thatis placed anterior to the patient’s chest. It uses80-120kVandfocusfilmdistanceof6feet.OnaPAfilm, lung is divided radiologically into threezones:1. Upper zone extends from apices to lower

borderof2ndribanteriorly.2. Middle zone extends from the lower border

of2ndribanteriorlytolowerborderof4thribanteriorly.

3. Lowerzoneextendsfromthelowerborderof4th rib anteriorly to lung bases. Please notethat radiological division of lung in upper,middle and lower zone does not depictanatomicallobesofthelung.

ANATOMICAL SEGMENTAL DIVISION OF LUNGS

Rightlunghasthreelobes:1. Upperlobewhichhasanapical,anterioranda

posteriorsegment.

2. Middlelobehasalateralandamedialsegment.3. Lower lobe has superior segment, medial

basal segment, anterior basal segment, lateral basalsegmentandaposteriorbasalsegment.

Leftlunghastwolobes:1. Upper lobe which has an apicoposterior,

anterior, superior lingular and an inferiorlingularsegment.

2. Lowerlobehassuperiorsegment,anteriorbasalsegment,lateralbasalsegmentandaposteriorbasalsegment.Leftlunghasnomiddlelobe.

When viewing the chest X-ray PA view look for(Figs3.1to3.4):• Checkpatient’snameanddate• Lungfields• Hilum – Normally left hilum is higher than

righthilum• Cardiacshapeandborders• Mediastinum• Diaphragm—right diaphragm is higher than

leftdiaphragm• Costophrenic angles should be well-defined

andacute• Trachea should be slightly deviated to the

rightaroundtheaorticknuckle• Lookatbonesforanylesionsandfractures• Lookforsofttissueabnormalities• Lookattheareaunderthediaphragm.

When viewing the chest X-ray lateral view (Figs3.5and3.6):

X-ray—ChestC H A P T E R

3

X-ray—Chest 29

Figs 3.1A to E:CTscanmultiplanarreconstructed(MPR)imagesofthorax:(A)Viewfromfront;(B)Lateralview; (C)Viewfromback;(D)CTscancoronalsectionofthorax;(E)CTscanaxialsectionofthorax

Fig. 3.2:X-raychest—PAview

A B C

D E


Fig. 3.3:X-raychest—PAviewmediastinalborders

Fig. 3.4:X-raychestPAview—Cardiothoracicratio(Cardiothoracicratio=a+b c ;CardiothoracicratioisestimatedfromthePAviewofchesttocalculatethesizeofheart.Itistheratiobetweenthemaximumtransversediameterofheartandthemaximumwidthofthoraxabovethecostophrenicangles.a=Rightheartbordertomidline;b=Leftheartbordertomidlineandc=Maximumthoracicdiameterabovecostophrenicanglesfrominnerbordersofribs

X-ray—Chest 31

• Checkpatientnameanddate• Identify the diaphragms (gastric air bubble

liesunderthelefthemidiaphragm• Comparethelungfieldsinretrosternalspace,

retrocardiac space and supracardiac space,theyshouldallhavethesamedensityontheX-ray film

• Lookcarefullyattheretrosternalspace,amassinthisspacewillobliteratethisspaceturningit white on the X-ray film

• Check the position of horizontal fissure andobliquefissures

• Checkthedensityofthehila• Donotforgettocarefullyexaminethevertebral

bodiesonthechestX-raylateralview.

Lung Fissures

They are thickening of the septae in the lungparenchyma. For a fissure to be seen on aradiograph, theX-raybeamhas tobe tangentialto it.The right lung has horizontal and oblique

fissureswhile the left lung has only the obliquefissure. Thelocationofthesefissuresare:• OnchestX-ray,PAviewthehorizontalfissure

appears as a faint white line that runs fromthemidpointoftherighthilumtotheanteriorchestwall.

• OnchestX-ray,lateralviewtheobliquefissureruns obliquely downwards from the D4/D5vertebrallevel,crossingthehiluminfrontandcontinuing downward direction to end neartheanterior1/3rdofdiaphragm.

Locating Lesions of the Lungs

WeneedtohavebothPAandlateralviewstolocatealesiononchestX-ray.OnPAviewlocatethelungzonewherethelesionlies,alsolookatthebordersof the lesion well-defined/ill-defined/silhouettesign. On lateral view identify the horizontalfissureandobliquefissure.Afterthisisdonetrytolocalizethelesioncarefully:

Fig. 3.5:X-raychest—Lateralview


Fig. 3.6:X-raychest—Apicogram

Fig. 3.7:X-raychest—PAview(negative)tovisualizebonythorax

X-ray—Chest 33

• Lesion in right lung field– If the lesion lies posterior to the oblique

fissure it must lie within the lower lobe,doesnotmatterhowhighitappearsonthePAview.

– If the lesion lies anterior to the obliquefissure itmay be in the upper ormiddlelobe.

– Ifthelesionisbelowthehorizontalfissureitisinthemiddlelobe

– If the lesion lies above the horizontalfissureitisintheupperlobe.

• Lesion in left lung field– Ifthelesionisbehindtheobliquefissureit

mustbeinthelowerlobe.– If the lesion is anterior to the oblique

fissurethenitmustbeinupperlobe(thereisnomiddlelobeinleftlung).

IMPORTANT POINTS TO OBSERVE ON CHEST X-RAYS

• In a well-centered chest X-ray, medial endsof clavicles are equidistant from vertebralspinousprocess.Bothlungfieldsareofequalradiolucency.

• Both hila are concave outwards. Thepulmonary arteries, upper lobe veins andbronchi contribute to the making of hilarshadows(Fig.3.7).

• The normal length of trachea is 10 cm, itis central in position and bifurcates at T4-T5 vertebral level. Left atrial enlargementincreases the tracheal bifurcation angle(normalis60°to75°).Aninhaledforeignbodyis likely to lodge in the right lungdue to thefact that the rightmain bronchus is shorter,straighterandwiderthanleft.

• Mediastinumisthespacebetweenthelungs.Itisdividedintoasuperiorandaninferiorcom-partment. Superior compartment consistsof the thoracic inlet. Inferior compartment

has anterior, middle and posteriorsubcompartments. Retrosternal regionis included in the anterior compartment,heart lies in the middle compartment anddescending aorta with esophagus andparaspinal region is located in the posteriormediastinalcompartment.Thymusislocatedin the anterior part of superior as well asinferiorcompartmentofmediastinum.

• Normal heart shadow is uniformly whitewithmaximumtransversediameterlessthanhalfof themaximumtransthoracicdiameter.CardiothoracicratioisestimatedfromthePAviewofchest(Fig.3.4).Itistheratiobetweenthemaximumtransversediameteroftheheartandthemaximumwidthof thoraxabovethecostophrenic angles: a = right heart borderto midline, b = left heart border to midline,c = maximum thoracic diameter abovecostophrenic angles from inner borders ofribs.Cardiothoracic ratio=a+b/c.ThusonchestX-rayPAviewthecardiothoracicratioislessthan1/2themaximumthoracicdiameter,in children this cardiothoracic ratio may beincreased.Inadultsthenormalcardiothoracicratiois2:1.

• Borders of the mediastinum are sharp anddistinct (Fig. 3.3). The right heart border isformedbysuperiorvenacavasuperiorlyandrightatriuminferiorly,theleftheartborderisformed by the aortic knuckle superiorly, leftatrialappendageandleftventricleinferiorly.

• Therightventricleliesanteriorly,posteriortothe sternumand the right atrium lieson therightlateralside.Theleftventricleliesontheentire left side, theoutletof the leftventricleand the ascending aorta lie in the center oftheheart.Theleftatriumisthemostposteriorchamberof theheart.The inferior venacavaisseenfurthercaudallyjustatthesectionthediaphragm appears together with the upperpartofliver.

The standard projections requested for abdominal radiographs are (Figs 4.1 and 4.2):• Supine• Erect• Lateraldecubitus The radiation exposure of an abdominal radiograph is equivalent to 28 chest radiographs. Key to densities in abdominal radiographs:• Black—Gas• White—Calcifiedstructures• Grey—Softtissues• Darkergray—Fat• Intensewhite—Metallicobjects. Alwaysviewtheradiographusingaviewbox.The contrast of outlines of structures depends on the differences between their densities. Thesedifferences are less apparent on the abdominal radiograph as most structures are of similar density—Mainlysofttissue. On a routine supine, abdominal radiograph lookforthefollowing:• Dark margins outlining the spleen, liver,

kidneys, bladder and psoas muscles—Thisindicates intra-abdominal fat.

• Gas in—Bodyof stomach,descendingcolon,small intestines.

• Fecal matter in cecum gives it a mottledappearance, seen as a mixture of gray densities representing a gas-liquid-solid mixture.

• Pelvic phleboliths are small round/ovalcalcificdensitiesinpelviccavity

• Adarkskinfoldacrosstheupperabdomenisnormalfinding

• Check the bony pelvis, spine and visualizedribs

• Theheart shadow should be on the left sideabove the diaphragm

• Checkwhether theright ‘R’marker isplacedon the right side of the abdominal radiograph

• Make sure that the abdominal radiographcovers both the hemidiaphragms to the inguinal canal regions

• Checkthelungbases. On an erect abdominal radiograph the followingchangesoccurs:• Theairrises• Fluidgoesdownduetogravity• The transverse colon, small bowel loops and

kidneysdropdownabitlowerduetogravity• A slight increase in radiographic density in

lowerabdomen• The lung bases appear clearer as the

diaphragmsmovedownalittle• Theliverandspleenbecomemorevisible. The abdominal radiograph is most helpful in cases of acute abdomen. A normal initial abdominal radiograph does not exclude intra-abdominal trauma, follow up radiographs,ultrasound, CT scan and MRI (Figs 4.1A to E)may be necessary. Abnormal air-fluid levels become easier to visualize on erect abdominalradiographs. Gas under diaphragm is seen in

Abdominal RadiographC H A P T E R

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Abdominal Radiograph 35

cases of perforated viscus. Also remember not to waste any time if the patient’s condition iscritical,stabilizethepatientandshiftthepatientto operating theater if needed. Radiationexposureinearlypregnancycanbedisastrous. It is always safer in femalepatientsofreproductiveagegroup tocheck thedateof theirlast menstrual period. Written consent form isneededconfirmingthatthepatientisnotpregnant/unlikelytobepregnantatthetimeofexamination. Additional points to note while examiningabdominal radiographs:• Maximumdiameterofsmallbowelshouldnot

exceed3cmandthatoflargebowelbymorethan 5 cm in diameter.

• Cecumissaidtobedilatedifitmeasuresmorethan 8 cm.

• Thehaustraofthelargebowelextendsonlyathird of theway across the bowel from eachside,whereasthevalvulaeconniventesofthesmallboweltraversefromwalltowall.

• Presenceofsmallamountsofintraluminalgasthroughout the gut is normal, but if found in excessmaybeabnormal.Alsoabsenceofbowelgasinoneareamayindicatebowelpathology.

• Presence of extraluminal gas is abnormal(lookforitunderthediaphragm,inthebowelwall,inbiliarysystem).

• Metallic objects may appear as brightdensities, so ask for appropriate history of

Figs 4.1A to E:CTscan(AtoC)multiplanarreconstructedimagesofabdomen:(A)Coronalview;(B)Sagittalview;(C)Axialview;(D)MRI-T2WIcoronalsectionofabdomen;(E)MRI-T2WIaxialsectionofabdomen

A B C

D E


Fig. 4.2:X-rayabdomen—Supineview

operations, trauma, ingestion of foreign body, therapeutic/diagnosticprocedures.

• Look for nasogastric tube placements,catheters, etc. to mention them in the report.

• Look for normal calcified structures whichcan cause diagnostic difficulty—excessivecostal cartilage calcification, calcified aortic/splenic arteries, pelvic phleboliths, calcifiedmesenteric lymph nodes, etc.

• Normalliverhasafairlypointedtip,ifthistipappears more rounded with displacementof adjacent intra-abdominal structures it is suggestive of hepatomegaly.

• Thespleenisnotnormallyseenonabdominalradiographs, when spleen is enlarged morethan 15 cm, it displaces the adjacent intra-abdominal organs and becomes more obvious on abdominal radiographs.

• Normalkidneysextendfromthelowermarginof 12th dorsal vertebra to the upper margin of

3rdlumbarvertebra,theleftkidneyisusuallyslightlylargerinsizeandslightlyhigherplacedascomparedtotherightkidney.Theoutlineofkidneyvisibleonabdominalradiographisdueto perinephric fat.

• An abdominal mass can arise anywhere inabdomen and would produce a dense areawith displacement of bowel loops around it,calcificationmayalsooccurwithinit,CTscanmaybe required to investigate such masses.

• Afullbladderappearsinthepelviccavityasasmooth rounded mass of uniform density, the outline is due to perivesical fat tissue.

• Retroperitoneal masses usually obscureor displace the psoas muscle outline on abdominal radiographs.

• Anerectchestradiographandnotabdominalradiograph is the best projection to diagnose a small pneumoperitoneum (gas in the peritoneal cavity).

SHOULDER JOINT

It is a ball and socket joint and can produce a range of movement such as adduction, abduction, extension and flexion. The head of humerus articulates with the shallow glenoid cavity of scapula thus connecting the upper limb to the chest (Figs 5.1A and B). The joint is made more stable by the articular capsule, ligaments, glenoid labrum and the rotator cuff. The labrum is a fibrocartilaginous rim attached

around the margin of the glenoid cavity. It deepens the articular cavity, cushions and stabilizes the humeral head. The articular capsule completely encircles the joint; it is attached to the circumference of the glenoid cavity beyond the labrum. The ligaments of the glenohumeral joint are coracohumeral ligament and glenohumeral ligament. The rotator cuff surrounds the shoulder joint; it is formed by tendons of four muscles—Supraspinatus, infraspinatus, teres minor, subscapularis and inserts into anatomical neck

Figs 5.1A and B: (A) Multiplanar reconstructed CT scan image of shoulder joint; (B) MRI-T1WI coronal section of shoulder joint

A B

Upper LimbC H A P T E R

5


and tuberosities of humerus. The rotator interval is the portion of the joint capsule which lies between the supraspinatus and subscapularis tendons. On AP view of shoulder joint (Figs 5.2 and 5.3) the normal acromioclavicular distance is <8 mm, coraco-clavicular distance is <13 mm, and the inferior margin of clavicle is in line with the inferior acromion.

UPPER ARM

Humerus is the long bone of upper arm. The head of humerus articulates with scapula superiorly at shoulder joint (Figs 5.4 and 5.5); inferiorly the humerus articulates with radius and ulna at elbow joint. The humerus at its upper end has a head and neck. The head of humerus is rounded almost like a sphere and is about four times the size of the glenoid cavity of scapula with which it articulates. The head of humerus

has two bony projections called the greater and lesser tuberosities which serve as attachments for muscles around the shoulder joint (Figs 5.6 and 5.7). The surgical neck of humerus lies at the junction with the shaft of humerus. The axillary nerve runs behind this neck and is likely to be injured in fractures of neck of humerus. The deltoid tuberosity is a bony prominence at the middle of the lateral side of shaft; and provides attachment to the fibers of deltoid muscle. The lower end of the humerus has articular surfaces for the elbow joint, capitulum and trochlea. The capitulum articulates with the head of radius while the trochlea partly articulates with the ulna. The olecranon fossa found on the posterior aspect of humerus at the distal end. Provides articulation for olecranon process of ulna. The medial and lateral epicondyles are projections of humerus, which provide attachment for muscles around the elbow joint.

Fig. 5.2: X-ray shoulder joint—AP view

Upper Limb 39

Fig. 5.3: X-ray shoulder joint—Axial view

Fig. 5.4: X-ray shoulder joint—Transthoracic view

The soft tissues comprise mainly of muscles, arteries, veins and nerves and are divided by a medial intermuscular septum into anterior and posterior compartments. The biceps brachii,

brachialis and coracobrachialis muscles lie in the anterior compart ment. The triceps brachii and anconeus muscles lie in posterior compartment. The main action of biceps brachii is to supinate


Fig. 5.6: X-ray upper arm—AP view

Figs 5.5A and B: (A) Multiplanar reconstructed CT scan image of upper arm; (B) MRI-T1WI sagittal section of upper arm

A B

Upper Limb 41

the forearm. The main action of brachialis muscle is to flex the forearm. Both the biceps brachii and brachialis muscle are innervated by the musculocutaneous nerve (C5 and C6). The main action of coracobrachialis muscle is to flex and abduct the arm. It is innervated also by musculocutaneous nerve (C5, C6, and C7). The main action of triceps brachii muscle is extension of forearm. It is innervated by the radial nerve (C6, C7 and C8). The main action of anconeus is to stabilize the elbow and assist triceps brachii in extension.

ELBOW JOINT

Elbow joint is a hinge-type of synovial joint formed by the distal humerus, proximal ulna, and radius (Fig. 5.8). The distal aspect of the humerus is flat and the medial third of its articular surface, the trochlea, articulates with the ulna while the

lateral capitulum articulates with the radius. On the posterior surface of the humerus is a hollow area, the olecranon fossa (Figs 5.9 and 5.10). The posterior capsular attachment of the humerus is located above the olecranon fossa. The anterior aspect of the distal humerus contains two fossae, the coronoid fossa, located medially, and the radial fossa, located laterally. The anterior capsular attachment to the humerus is located above these fossae. The proximal end of the ulna has the olecranon and the coronoid process (Fig. 5.11). The radial head has a round shallow articular surface which articulates with the capitulum of the humerus. A fibrous capsule envelops the elbow joint; and a synovial membrane outlines the deep surface of this fibrous capsule. A number of fat pads are located between the fibrous capsule and the synovium. The muscles around the elbow

Fig. 5.7: X-ray upper arm—Lateral view


Fig. 5.9: X-ray elbow joint—AP view

Figs 5.8A and B: (A) Multiplanar reconstructed CT scan image of elbow joint; (B) MRI-T1WI coronal section of elbow joint

A B

Upper Limb 43

Fig. 5.10: X-ray elbow joint—Lateral view (in flexion)

Fig. 5.11: X-ray elbow joint—Oblique view (in extension)

joint comprise of posterior, anterior, lateral, and medial groups. The muscles of the posterior group are the triceps and the anconeus. The muscles of the anterior group are the biceps and

brachialis. The lateral group of muscles includes the supinator and brachioradialis muscles and the extensor muscles of the wrist and hand. The medial group of muscles includes the pronator


Figs 5.12A and B: (A) Multiplanar reconstructed CT scan image of forearm; (B) MRI-T1WI coronal section of forearm

teres, the palmaris longus, and the flexors of the hand and wrist.

FOREARM

The radius is a long bone on the lateral side of forearm. It has a cylindrical head and articulates with the capitulum at elbow joint (Figs 5.12 and 5.13). It has a narrow neck below which is the long shaft of radius. The radius has a bony prominence on its medial side called the radial tuberosity (Fig. 5.14). Distally, the radius articulates with the proximal row of carpal bones, known as the radiocarpal joint. The styloid process of radius is bony projection on its lateral side at the radiocarpal joint. On its medial aspect at the radiocarpal joint it has a small facet to articulate with the ulna. The ulna is the long bone on the medial side of forearm. It has an olecranon process at the elbow joint which articulates with the olecranon fossa of humerus on posterior aspect of elbow joint. The coronoid process of ulna is a bony prominence on the anterior aspect of ulna at the elbow joint. The lower part of coronoid process is called the ulnar tuberosity, which serves as attachment to the brachialis muscle. Between the coronoid process and the olecranon process of ulna there is a saddle-like depression which articulates with the trochlea of humerus. The shaft of ulna provides attachment to the muscles of forearm and wrist. At the wrist joint the ulna narrows down, it has a bony projection on its medial side called the styloid process. The lateral side of ulna at the wrist has a surface that articulates with the radius, this is called as distal radioulnar joint. The ulna articulates with the proximal row of carpal bones on medial side, called as carpoulnar joint. The anterior muscle group comprises of: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus and pro nator quadratus. The posterior muscle group comprises of: brachioradialis, extensor carpi radialis longus,

A B

exten sor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis.

WRIST JOINT AND HAND

The small bones of the hand can be classified into carpal bones, metacarpal bones and phalanges. The carpal bones are made up of two rows of eight carpal bones forming a semicircle (Figs 5.15A and B). The proximal row lies where the wrist creases on bending the wrist. From lateral to medial, the

Upper Limb 45

Fig. 5.13: X-ray forearm—AP view

Fig. 5.14: X-ray forearm—Lateral view


Figs 5.15A and B: (A) Multiplanar reconstructed CT scan image of hand and wrist joint, (B) MRI-T1WI coronal section of wrist joint

proximal row of carpal bones is made up of the scaphoid, lunate, triquetrum and pisiform. The distal row is made up of the trapezium, trapezoid, capitate and hamate bones (Figs 5.16 to 5.18). The distal row of carpal bones articulates with the bases of metacarpals in hand. All the carpal bones are surrounded and supported by the joint capsule containing synovial fluid. The scaphoid is boat-shaped bone. Its convex surface articulates with radius, its medial surface articulates with lunate, laterally it articulates with trapezium and trapezoid. The waist of scaphoid is narrower and more likely to fracture in trauma. The lunate has a semilunar shape and it articulates with radius at the wrist. It also articulates with the scaphoid and triquetral bones in proximal row of carpal bones.

The lunate is the most commonly dislocated carpal bone. The triquetral bone articulates with the pisiform, hamate and lunate bones. The pisiform articulates with the triquetral bone. The trapezium articulates with the trapezoid, scaphoid and also with the bases of the first and second metacarpals. The trapezoid is a small bone, it articulates with the scaphoid, trapezium, capitate and partly with base of second metacarpal. The capitate lies between the hamate medially and trapezoid laterally. It articulates with the base of third metacarpal and partly with base of fourth metacarpal. The hamate is wedge-shaped carpal bone. Proximally it articulates with lunate and distally it articulates with bases of fourth and fifth metacarpals. The metacarpal bones are

A B

Upper Limb 47

Fig. 5.17: X-ray hand and wrist joint—AP view

Fig. 5.16: X-ray hand and wrist joint oblique view


Fig. 5.18: X-ray both wrist joints, AP view in an 18-month-old child

5 in number, they articulate with the carpal bones proximally, while distally they articulate with their respective phalanges. The phalanges articulate with heads of metacarpals proximally at metacarpophalangeal joint. The first digit has two phalanges while the rest of digits have three phalanges. The wrist joint comprises of bones and joints, ligaments and tendons. The distal end of ulna articulates with lunate and triquetrum. The distal end of radius articulates with scaphoid and lunate, this is also called as radiocarpal joint. The distal radioulnar joint is a pivot joint that allows pronation and supination of wrist joint. It is formed by the head of ulna and the ulnar notch of radius; this joint is separated from the radiocarpal joint by an articular disk lying between the radius

and the styloid process of ulna. The tendons that cross the wrist begin as muscles that start in the forearm. The radial and ulnar collateral ligaments stabilize the wrist joint. Those that cross the palmar side of the wrist are the flexor tendons. Those tendons that travel at the back of wrist are the extensor tendons.

HANDThe metacarpal bones are five in number, its bases articulate with the distal row of carpal bones. This articulation is known as carpometacarpal joints. The head of the metacarpal bones arti culate with the base of phalanx, it is called as metacarpophalangeal joint. Between the phalanges are the proximal and distal interphalangeal joints.

HIP JOINT

On plain X-rays, the hip joint is appreciated on AP, lateral and postero-oblique views (Figs 6.1 to 6.5). The hip joint is a multiaxial synovial joint (ball and socket joint). It comprises of the head of femur articulating with the acetabular cavity of the hip bone. The hip joint is supported by muscle and ligaments which not only provide stability, but also produce a range of movements at the joint. The three parts of the hip bone are ilium, ischium and pubis, they join together at the acetabulum to form the triradiate synchondrosis. The acetabular labrum is attached to the acetabular rim and the transverse acetabular ligament. It forms a complete ring encircling the head of femur which fits into the acetabular cavity (Figs 6.2 and 6.3). Movements at the hip joint include flexion (normal range 120o), extension (normal range 20o), adduction (normal range 30o), abduction (normal range 60o), medial and lateral rotation (normal range along a vertical axis 40o). The fibers of the capsule become stiffer during movements like extension and medial rotation of the femur. The ligament of head of femur connects the head of femur to the acetabular cavity. The ligament of the head of femur becomes stiffer during adduction movement of the hip joint, when the legs are crossed in front. Major anastomosis occurs around the femoral neck involving branches from the femoral

arteries (medial and lateral circumflex branches) and obtu rator artery branches. As the medial circumflex artery supplies a major portion of blood to the head and neck of femur, in fracture of femoral neck this blood supply is disrupted and the head of femur may undergo avascular necrosis. The obturator artery divides into anterior and posterior branches. The acetabular artery is a branch of the posterior branch of obturator artery. The acetabular branches pass through the acetabular foramen and enter the aceta bular fossa where they diverge in the fatty tissue. The nutrient branches radiate to the margins of the acetabular fossa to enter the nutrient foramina. Radiological interventions like aspiration or injec tions into the hip joint can be done anteriorly or from the side, laterally. In case of lateral approach to hip joint the needle passes in front of the greater trochanter and parallel to the femoral neck to enter the joint capsule. In the anterior approach, the needle is inserted just below the anterior inferior iliac spine and directed upwards and medially into the joint capsule.

Important Radiologic Lines of Hip Joint Position

Hilgenreiner’s line: It is a line connecting the superolateral margins of triradiate cartilage.

Perkin’s line: It is a vertical line to the Hilgenreiner’s line through the lateral rim of acetabulum.

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Figs 6.1A to D: CT scan multiplanar reconstructed (MPR) images of pelvis with hip joints: (A) Anterior view; (B) As seen from below; (C) Oblique view; (D) MRI-T1WI hip joint coronal section

Acetabular angle: It is the angle that lies between Hilgenreiner’s line and a line drawn from supero-lateral ossified edge of triradiate cartilage. Acetabular angle > 30o suggest hip joint dysplasia.

Shenton’s curved line: It is an arc formed by inferior surface of superior pubic ramus and medial surface of proximal femur to the level of lesser trochanter.

Center-edge angle: It is the angle formed by a line drawn from the acetabular edge to the center of femoral head, a second line is drawn perpendicular to the first line thereby connecting

the centers of femoral heads. Radiologically, if this angle is less than 25o it suggests femoral head instability.

THIGH

On plain X-rays, the thigh is appreciated on both AP, lateral and posterior oblique views (Figs 6.6 to 6.9). The thigh comprises of the femur along with soft tissues (mainly muscle groups). The femur has a long shaft, the proximal end of femur has a rounded head and a slender neck, the distal end of femur at the knee has

A B

C D

Lower Limb 51

Fig. 6.2: X-ray pelvis with both hip joints—AP view

Fig. 6.3: X-ray right hip joint—AP view


Fig. 6.4: X-ray hip joint—Posterior oblique view

Fig. 6.5: X-ray hip joint with pelvis—Lateral view

Lower Limb 53

Figs 6.6A to E: (A) CT scan topogram of thigh with both hip joints; (B to D) CT scan multiplanar reconstructed (MPR) images of femur with hip joint; (B) Anterior view; (C) Lateral view; (D) Posterior view; (E) MRI-T1WI coronal section of femur with hip joint

two condyles that articulate with the upper end of tibia. The head of femur has the fovea on its medial surface where the ligament of head attaches to it. The neck of femur has an angle of around 125° with the shaft of femur and slightly tilted forwards. The greater trochanter projects upwards and backwards from the junction of the neck and shaft of femur, it is slightly pyramidal in shape with its apex pointed outwards. The lesser trochanter arises from the lowermost part of the neck of femur on the posterior aspect of femur. Between the greater trochanter and lesser trochanter anteriorly lies the intertrochanteric line, posteriorly lies the intertrochanteric crest. The shaft of femur is long and gives attachment

to muscles. At the lower end of femur are two condyles, lateral condyle and medial condyle. Between these condyles lies the intercondylar fossa. The muscle groups of the thigh provide support to the hip and knee joints and help in movement. The main muscle groups are—The anterior, medial, gluteal region, posterior thigh muscles and iliotibial tract on lateral aspect. The muscles of the anterior thigh are the iliopsoas and quadriceps femoris. The iliopsoas muscle group consists of the psoas major, iliacus, tensor fascia lata and sartorius. The main action of this group of muscles at the hip is flexion and medial rotation.

A

B C

D E


Fig. 6.7: X-ray thigh (femur)—AP view

Fig. 6.8: X-ray thigh (femur)—Lateral view

Lower Limb 55

Fig. 6.9: X-ray thigh (femur)—Postero-oblique view

The quadriceps femoris muscles comprise of the rectus femoris, vastus lateralis, vastus medialis and vastus intermedius muscles. The quadriceps group of tendons fuse together and attach to the base of the patella. The patella in turn through the patellar tendon is attached to the tibial tuberosity. The main action of quadriceps group of muscles is extension at knee joint. The muscles of the medial aspect of thigh are the pectinius, adductor longus, adductor brevis, adductor magnus, gracialis and obturator externus muscles. The action at the hip is adduction and flexion movements. The muscles of the gluteal region are gluteus maximus, gluteus medius, gluteus minimus, pyri-formis, obturator internus, gemelli (superior and

inferior), and quadratus femoris. These muscles assist in extension, abduction, medial and lateral rotation at the thigh. The muscles of the posterior thigh are hamstring muscles—Semitendinosus, semimembranosus and biceps femoris muscles. Their main action is exten sion, flexion and medial rotation of the leg.

KNEE JOINT

On plain X-rays, the knee joint is appreciated in AP and lateral views (Figs 6.10 to 6.12). Additional views like the patellar (skyline) view may be necessary to visualize the patellofemoral joint spaces (Fig. 6.13). The knee joint is a modified pivotal hinge joint. It is the largest synovial joint


Figs 6.10A to D: CT scan (A and B) multiplanar reconstructed images of knee joint: (A) Anterior view; (B) Lateral view, MRI-T1WI images; (C) Coronal section; (D) Sagittal section

in the body. The synovial fluid is around 0.5 ml normally to prevent friction in joint spaces. The knee joint consists of two condylar joints between the femur and the tibia and a saddle joint between the patella and the femur, the capsule of knee joint is attached to the articular margins of these bones. The intercondylar eminence of the tibia prevents sideway slipping of femur on tibia. The ligaments and muscles make knee a very stable joint. The medial and lateral articular surfaces of the femur and tibia are asymmetrical. The distal surface of the medial condyle of the femur is narrower

and more curved than the lateral condyle. The articular surface of lateral tibia is almost circular whereas the medial surface is oval in shape. The articular surface of patella has a larger lateral and a smaller medial surface. The knee joint is stabilized by the surrounding muscles and their tendons. Anteriorly, it is the quadriceps tendon. This broad tendon attaches to and surrounds the patella and continues as the patellar ligament, which is attached to the tuberosity of the tibia. Posteriorly are the popliteus, plantaris and medial and lateral heads

A B

C D

Lower Limb 57

Fig. 6.11: X-ray knee joint—AP view

Fig. 6.12: X-ray knee joint—Lateral view


Fig. 6.13: X-ray knee joint skyline, view for patella

of gastrocnemius. Laterally are the tendons of the biceps femoris and popliteus. Medially are the sartorius, gracialis, semitendinosus and semimembranosus muscles. The ligaments of knee joint include the cruciate ligaments, arcuate popliteal ligament, the oblique popliteal ligament, fibular collateral ligament and the tibial collateral ligament. The patellar ligament is a central band of the tendon of quadriceps femoris muscles; it is about 8 cm long. Proximally, it attaches to the anterior and posterior surfaces of patella including the apex. Distally it attaches to the smooth area of tibial tuberosity. The menisci are called semilunar cartilages. These are cresenteric disks of fibrocartilage that act as shock absorbers. The menisci are avascular structures comprising mainly of collagenous fibrous tissue attached to the tibial plateau. There are two menisci, the lateral and the medial meniscus. Movements at the knee joint are the flexion (normal range 150o), extension (normal range 30o), medial and lateral rotation (normal 5–10o).

Blood supply to knee joint is by anastomosis of the genicular branches of the popliteal artery. The middle genicular branches supply the cruciate ligaments. Bursae of knee joint reduce the friction between tendon and bones. The suprapatellar bursa lies between the femur and the quadriceps femoris. The prepatellar bursa lies between the skin and the patella. The infrapatellar bursa lies between the skin and the tibial tuberosity. The deep infrapatellar bursa lies between the patellar ligament and the upper part of the tibia. The semimembranosus bursa lies between the medial collateral ligament and the tendon of the semimembranous.

LEG

On plain X-rays, the tibia and fibula are appreciated on both AP and lateral views. Either the ankle joint or the knee joint is included to provide the radiologist a landmark to assess and report the abnormality on plain X-rays.

Lower Limb 59

The tibia is a long bone on the medial aspect of leg; it has a larger upper end at the knee joint and a rather smaller lower end at the ankle joint. At the knee joint the upper end of tibia has a superior articular surface (plateau-like surface), and divided by the intercondylar eminence into two unequal surfaces (medial and lateral surfaces). The medial surface is larger than the lateral surface, they articulate with the medial and lateral condyles of femur. The shaft of tibia is more triangular in shape and provides attachment to the muscle of knee joint and leg. The lower end of tibia has a prominence called the medial malleolus on its medial side at the ankle joint. The tibia articulates with the talus at the ankle joint (talocrural joint). The fibula is a slender long bone on the lateral aspect of leg. The head of fibula has a facet to articulate with the upper end of tibia. The shaft has surfaces for muscle attachments. The common peroneal nerve run close to the neck of fibula and in case of fracture to the neck of fibula the nerve

can get injured. The lower end of fibula at ankle has a prominence on its lateral aspect called as the lateral malleolus (Figs 6.14 to 6.16). Soft tissues of the leg are mostly made of muscles. These muscles are grouped into compartments for description purposes. The anterior group of muscles comprises of tibialis anterior, extensor hallucis longus, extensor digitorum longus and peroneus tertius muscles. Their main action is dorsiflexion at ankle, inversion of foot, eversion of foot, extend the great toe and the four lateral digits. The lateral group of muscles comprises of peroneus longus muscle, peroneus brevis muscles. Their main action is eversion of the foot and plantar flexion of the ankle. The posterior group of muscles are classified into two subgroups—Superficial group and deep group of muscles. The superficial group comprises of gastrocnemius, soleus and plantaris muscles. Its main action is to assist in plantar flexion of ankle and flexion at knee joint. The deep group

Figs 6.14A to E: CT scan multiplanar reconstructed images of lower leg with ankle: (A) Anterior view; (B) Medial view; (C) Lateral view; (D) Posterior view; (E) MRI-T1WI coronal section of lower leg

A B C D E


Fig. 6.15: X-ray leg (tibiofibula)—AP view

of muscles comprises of popliteus, flexor hallucis longus, flexor digitorum longus, tibialis posterior muscles. Its main action is flexion at knee joint, flexion at great toe, plantar flexion at ankle, flexion of lateral four digits and inversion of the foot.

ANKLE JOINT

On plain X-rays, the ankle joint (talocrural joint) is appreciated on AP and oblique views. The articular surfaces of the lower ends of tibia and fibula, the upper ends of talus and calcaneus constitute the ankle joint (Figs 6.17 to 6.21). The body weight is transmitted through the tibia to the talus which distributes anteriorly and posteriorly within the foot. The muscles and ligaments around

the ankle joint provide stability and movements possible at the ankle joint. The ankle joint has two groups of ligaments—The lateral collateral ligaments and the medial collateral ligaments. These ligaments are strong fibrous bands and they are extremely important in the stability of the ankle joint. The lateral collateral ligament prevents excessive inversion and comprises of anterior talofibular ligament, calcaneofibular liga ment and posterior talofibular ligament. The medial collateral ligament or the deltoid ligament is thicker than the lateral ligament and spreads in a fan shape manner to cover the distal end of the tibia and the inner surfaces of the talus, navicular, and calcaneus.

Lower Limb 61

Fig. 6.16: X-ray leg (tibiofibula)—Lateral view

Figs 6.17A to C: CT scan multiplanar reconstructed images of ankle joint: (A) Anterior view; (B) Posterior view; (C) MRI-T1WI coronal section of ankle joint

A B C


Fig. 6.18: X-ray ankle joint—AP view

Fig. 6.19: X-ray ankle joint—Lateral view

Lower Limb 63

Figs 6.20A to F: CT scan multiplanar reconstructed images of foot with ankle: (A) Medial view; (B) Anterior view; (C) Posterior view; (D) Lateral view; (E) View from below; (F) MRI-T1WI sagittal section of foot with ankle

Fig. 6.21: X-ray ankle and foot—Lateral view

A B C

D E F


Fig. 6.22: X-ray foot showing the location of arches of foot

Fig. 6.23: X-ray foot—AP view

Lower Limb 65

The medial collateral ligament or deltoid ligament includes the tibionavicular ligament, calcaneotibial ligament, anterior talotibial ligament and the post erior talotibial ligament. They prevent abduction and limit plantar flexion and dorsiflexion of the ankle joint. Tarsal joints at ankle: comprises of the talocal-caneonavicular joint, talocalcaneal joint and the calcaneocuboid joint. The main action at these joints is inversion and eversion at ankle joint. The talocalcaneonavicular joint is a synovial joint of the ball and socket type. The ball is formed by the head of talus; the socket is formed by the navicular, calcaneus and spring ligament. The posterior surface of navicular is concave and articulates with the head of talus which is convex-shaped. The inferior convexity of head

of talus articulates with the calcaneus at the sustentaculum tali. Between the articular surfaces of talus with the navicular and calcaneus, the head of talus articulates with the spring ligament. The talocalcaneonavicular joint is enclosed in a single capsule. The talocalcaneal joint lies behind the talocal-caneonavicular joint. The calcaneocuboid joint is a synovial joint between the anterior surface of calcaneus and the back of the cuboid. The talonavicular part of talocalcaneonavicular joint and the calcaneocuboid joint form the midtarsal joint. Radiological interventions like aspiration of the ankle joint is possible - from lateral side of ankle joint, directing the needle in front of the lateral malleolus and lateral to the tendon of

Fig. 6.24: X-ray foot—Oblique view


peroneus tertius muscle to enter the joint capsule. It is also possible to direct the needle from the medial side of ankle, in front of the medial malleolus and medial to tibialis anterior muscle to enter the joint capsule.

FOOT

On plain radiographs, the foot is appreciated on AP, oblique and lateral views. The tarsal bones are Navicular, cuboid, cuneiform bones (medial, intermediate and lateral). The metatarsal bones articulate with the tarsal bones proximally and distally they articulate with the phalanges. The interphalangeal joints are similar to the joints of hand with capsules and collateral ligaments. The first tarsometatarsal joint has its own capsule and synovial membrane, some movements in vertical plane possible along with the medial longitudinal arch of foot. The second tarsometatarsal joint

is immobile, in addition its slender metatarsal shaft makes it prone for injury, it is a commonly involved site in “March fractures”. Supporting mechanisms of the foot are the arches of the foot namely, medial longitudinal arch, lateral longitudinal arch and the transverse arch. The arches are formed by the bony undersurfaces of the bones of foot with the ligaments and muscles. Due to the upright posture and bodyweight transmitted to the foot, these arches help to act as shock absorbing mechanism and propulsion to some extent. The medial longitudinal arch is formed by the undersurfaces of the calcaneus, talus, navicular, three cuneiform bones and their three metatarsal bones (Figs 6.20 to 6.24). The lateral longitudinal arch is formed by undersurfaces of calcaneus, cuboid, and the two lateral metatarsal bones. The transverse arch is formed by the undersurfaces of bases of five metatarsal bones, cuboid and cuneiform bones.

CEREBRAL CIRCULATION

Normal Intracranial Arterial System

Branches of the aortic arch: Brachiocephalic artery, the left common carotid artery, and left subclavian artery (Flow chart 7.1).

The extracranial carotid arteries: The right common carotid artery usually arises from the bifurcation of the brachiocephalic artery. The left common carotid artery arises from the aortic arch distal to the origin of brachiocephalic artery. Both the right and left common carotid arteries bifurcate into the external and internal carotid arteries on either side at C4- C5 level.

Branches of the external carotid artery: Superior thy roidal artery, ascending pharyngeal artery, lingual artery, occipital artery, facial artery, posterior auri cular artery, internal maxillary artery and superficial temporal artery. The internal maxillary artery branches are super ficial temporal artery, middle meningeal artery, accessory meningeal artery and anterior deep tem poral artery. The superior thyroid artery supplies the thyroid and larynx. The ascending pharyngeal artery supplies the nasopharynx and tympanic cavity. The lingual artery supplies the tongue, floor of the mouth and submandibular gland. The occipital artery supplies the scalp and upper cervical musculature.

Facial artery branches supply the palate, pharynx, orbit, face and important anastomosis with other external carotid artery branches. The superficial temporal artery and posterior auricular arteries supply the scalp, buccal region and ear structures. The internal maxillary artery gives vascular supply to temporalis muscles, meninges, paranasal sinuses and mandible. While traversing the foramen spinosum, the middle meningeal artery may supply a branch, through the petrous bone, to the facial nerve.

Internal carotid artery: The intracranial portions are petrous and cavernous portions.

Petrous portion of internal carotid artery: The ICA while passing through the carotid canal, gives of the Vidian artery which anastomoses with the basilar artery of posterior circulation.

Cavernous portion of internal carotid artery: It gives off the following branches—Meningohypophyseal trunk, inferolateral trunk, ophthalmic artery, posterior communicating artery, anterior choroidal artery, anterior and middle cerebral arteries. The ophthalmic artery is the first branch of the supraclinoid portion of the ICA and thus serves as a demarcation between the intracavernous and subarachnoid segments of the ICA. The posterior communicating artery (PCOM) connects the ICA with vertebrobasilar circulation

AngiogramsC H A P T E R

7


Flow chart 7.1: Cerebral circulation

(P1 segment of ipsilateral posterior cerebral artery). The posterior communicating artery supplies the thalamus, hypothalamus and optic chiasm. The anterior choroidal artery originates from ICA, it supplies the choroid plexus of lateral ventricle and anastomoses with lateral posterior choroidal artery. The occlusion of anterior choroidal artery can cause hemiplegia,

Flow chart 7.2: Internal carotid artery branches

hemiparesis, homonymous hemianopia as its minute perforators supply the internal capsule, thalamus, basal ganglia (Flow chart 7.2).

Circle of Willis: It is an important collateral system at the base of the brain surrounding the optic chiasm and pituitary stalk. It comprises of—the basilar artery bifurcation (basilar tip), P1 segments of posterior cerebral artery proximal

Angiograms 69

segments, paired distal ICA’s, paired posterior communicating arteries (PCOM), paired proximal A1 segments of ACA’s and the anterior communicating artery (ACOM). This vascular ring is complete only in about 25 percent of cases (Fig. 7.1). Perforating vessels arising from the circle of Willis include branches to the thalamus, limbic system, reticular activating system, cerebral peduncles, posterior limb of internal capsule and oculomotor nerve nucleus. The recurrent artery of Heubner originates from the A1 segment to supply the anterior limb of internal capsule, portion of the globus pallidus and head of the caudate nucleus.

The anterior cerebral artery: The most proximal segment is the A1 segment, its origin at the terminal ICA to the anterior communicating artery (ACOM). A2 segment is the portion distal

Fig. 7.1: Circle of WillisAbbreviations: ACA: Anterior cerebral artery; ACom: Anterior communicating artery; MCA: Middle cerebral artery; ICA: Internal carotid artery; PCom: Posterior communicating artery; PCA: Posterior cerebral artery; SCA: Superior- internal carotid artery; Basilar: Basilar artery; AICA: Anterior cerebral artery; VA: Vertebral artery; ASA: Anterior spinal artery

to the ACOM and extends into the distal ACA. The A2 segment supplies the head of the caudate nucleus, portions of the globus pallidus, anterior limb of the internal capsule, anterior two-thirds of medial cerebral cortex. The main branches of the A2 segment are the orbitofrontal and frontopolar arteries. The ACA bifurcates into the pericallosal and callosomarginal arteries (Figs 7.2 to 7.6).

The middle cerebral artery: The most proximal segment is M1 segment. It extends from ICA bifurcation to the insular cortex (island of Reil). M2 segment is the course of the artery in the insular cortex and sylvian fissure and it bifurcates into anterior and posterior cortical branches. The branches of the anterior cortical M2 segment are lateral orbitofrontal, operculofrontal and central sulcus arteries. The central sulcus arteries are called precentral (prerolandic) and central (rolandic) bran ches which supply motor and sensory cortical strips. The branches of posterior cortical M2 segment are the anterior and posterior parietal, angular and posterior temporal arteries (Figs 7.2 to 7.6).

The Vertebrobasilar Circulation

Vertebral arteries: The vertebral arteries originate from the subclavian arteries. One of the vertebral arteries may be dominant in size as compared to the other. Each vertebral artery passes through the transverse foramen of C6 and passes superiorly through the transverse foramina of C5 to C1, then it courses posteriorly around the atlanto-occipital joint and ascends through the foramen magnum, penetrating the atlanto-occipital membrane and dura. It gives off the posterior-inferior cerebellar artery and the anterior spinal arteries. It then travels superiorly around the lateral aspect of medulla to join with the contralateral vertebral artery to form the basilar artery at pontomedullary junction. The posterior inferior cerebellar artery (PICA) provides branches to the medulla, the occlusion of which can cause the lateral medullary syndrome or pyramidal tract ischemia. Lateral medullary


Fig. 7.2: Angiogram of right anterior cerebral circulation arterial phase—AP view

Fig. 7.3: Angiogram of right anterior cerebral circulation arterial phase—Lateral view

Angiograms 71

Fig. 7.4: Angiogram of right anterior cerebral circulation arterial phase—Lateral view

Fig. 7.5: Angiogram right anterior cerebral circulation capillary phase—AP view


Fig. 7.6: Angiogram of right anterior cerebral circulation capillary phase—Lateral view

Fig. 7.7: Angiogram of right anterior cerebral circulation venous phase—AP view

Angiograms 73

syndrome consists of ipsilateral Horner’s syndrome, facial sensory loss, pharyngeal/laryngeal paralysis, contralateral pain and temperature sensory loss in the limbs and trunk.

Anterior spinal arteries: It originates from the vertebral arteries distal to the posteroinferior cerebellar artery origin, they course inferomedially to join with their contralateral artery along the anterior cord.

Basilar artery: The two vertebral arteries join together to form the basilar artery at the pontomedullary junction. The basilar artery courses anterosuperiorly over the ventral pons. It gives off small pontine perforating branches which supply the pyramidal tracts, medial lemnisci, red nuclei, respiratory centers and nuclei for cranial nerves (III, VI, XII). The basilar artery gives off the anterior inferior cerebellar artery and the superior cerebellar artery. The labyrinthine artery is a branch of the anterior inferior cerebellar artery.

Superior cerebellar artery provides vascular supply to the cerebellar peduncles, vermis, dentate nucleus, lateral pontine structures, spinothalamic tracts and sympathetic.

Posterior cerebral arteries: Arise from the basilar artery at the level of pontomesencephalic junc-tion, superior to the oculomotor nerve and tentorium. The proximal PCA is divided into P1 and P2 segments at the junction of the PCA with the posterior communicating artery. A filling defect is frequently seen at the transition between P1 and P2 during frontal vertebral artery angiograms due to the inflow of unopacified blood from the ipsilateral posterior communicating artery. The proximal P2 segment gives rise to the posterior thalamoperforating and thalamogeniculate arteries which supply the posterior portions of the thalamus, geniculate bodies, choroid plexus of third and lateral ventricles, posterior limb of internal capsule, optic tract and small

Fig. 7.8: Angiogram of right anterior cerebral circulation venous phase—Lateral view


Fig. 7.9: Angiogram of posterior cerebral circulation arterial phase—AP view

branches to the cerebral peduncles. The other branches of posterior cerebral artery are the splenial artery, anterior and posterior temporal branches, parietooccipital artery. The distal PCA courses posteriorly around the brainstem in the ambient cistern, travelling more medially in the quadrigeminal plate cistern. The distal calcarine cortical branches converge towards the midline but are separated by falx, on Townes projection vertebral angiogram (Figs 7.9 to 7.12).

NORMAL INTRACRANIAL VENOUS SYSTEM

Cerebral cortical veins: Multiple cortical veins drain towards the superior sagittal sinus. The superficial middle cerebral vein which lies in the sylvian fissure may have anastomotic communication with the deep cerebral venous system, the facial veins and the extracranial pterygoid venous plexus. Posteriorly the superficial middle cerebral vein communicates with the veins of Trolard and Labbe towards the ipsilateral transverse sinus. The veins of Trolard

and Labbe cross the subdural space to enter the dural sinuses.

Deep cerebral veins: These are the paired septal veins which run close to midline beside septum pellucidum. The paired thalamostriate veins pass along the floor of the lateral ventricles between the body of caudate nucleus and thalamus. The internal cerebral veins run posteriorly in the roof of third ventricle. The paired basal veins of Rosenthal are formed by the confluence of deep middle and anterior cerebral veins on the ventral surface of brain. The basal veins then coalese posteriorly with the internal cerebral veins to form the vein of Galen (Figs 7.7 and 7.8). This vein of Galen travels in the midline for about 1–2 cm under the splenium of corpus callosum, it then joins the inferior sagittal sinus in the posterior fossa to form the straight sinus at the junction of falx and tentorial incisura (Flow chart 7.3).

The posterior fossa veins: These are the anterior pontomesencephalic veins, the precentral veins, superior and inferior vermian veins. The anterior

Angiograms 75

Fig. 7.10: Angiogram of posterior cerebral circulation arterial phase—Lateral view

Fig. 7.11: Angiogram of posterior cerebral circulation capillary phase—AP view


Fig. 7.12: Angiogram of posterior cerebral circulation capillary phase—Lateral view

pontomesencephalic vein runs along the ventral surface of pons, it drains either into the basal vein of Rosenthal or posterior mesencephalic vein (Figs 7.13 and 7.14). The precentral veins run along the posteriorly in the roof of fourth ventricle and drains into the vein of Galen (Flow chart 7.4).

Dural sinuses: The dura mater which envelops the central nervous system has two layers that form the reflections like the falx cerebri, tentorium and falx cerebelli. The layers of dura separate to form venous drainage channels or dural sinuses for the brain. Some of them anastomose with the veins of scalp through the emissary veins. The main dural sinuses found are the superior sagittal sinus, inferior sagittal sinus, occipital sinuses, paired transverse sinuses and paired cavernous sinuses (Figs 7.7 and 7.8). The superior sagittal sinus travels along the superior margin of falx cerebri, it continues

posteriorly and inferiorly in a cresenteric course to the junction point between the falx and tentorium containing the confluence of sinuses—The torcular Herophili near the occipital protuberance. The inferior sagittal sinus is found within the lower edge of falx between the cerebral hemispheres. It drains posteriorly to join with the vein of Galen forming the straight sinus. The straight sinus drains posteriorly in midline into the torcular herophili. The occipital sinuses are of variable size, are seen to course superomedially within the dura of the posterior fossa, just lateral to foramen magnum and drains towards the torcular herophili. The paired transverse sinus follows a cresenteric course within the periphery of the tentorium, laterally and anteriorly from the torcula. The transverse sinuses receive drainage from the inferior cerebral veins and vein of Labbe, it communicates with the cavernous sinuses via

Angiograms 77

Fig. 7.13: Angiogram of posterior cerebral circulation venous phase—AP view

Fig. 7.14: Angiogram of posterior cerebral circulation venous phase—Lateral view

the superior petrosal sinuses, which run along the petrous bone and as it nears the tentorium it is

called the sigmoid sinus which later empties into the internal jugular vein (Flow chart 7.5).


Flow chart 7.3: Normal venous anatomy of the brain

Flow chart 7.4: Posterior fossa veins and jugular bulb

Angiograms 79

The ascending aorta arises at the aortic root, from the left ventricle. Immediately above the aortic root, the ascending aorta bulges to form the aortic sinuses, the aortic sinuses give rise to right and left coronary arteries to supply the heart. The ascending aorta the courses upwards and continues as the aortic arch. The main branches of the aortic arch (arch of aorta) are the brachiocephalic trunk, left common carotid artery and the left subclavian artery (Figs 7.15

and 7.16). Sometimes the thyroidea ima artery may arise from the aortic arch. These branches of aortic arch supply the head, neck, brain and upper limbs (Flow chart 7.6). The aortic arch on plain chest X-ray appears behind the mediastinal structures in midline. The aortic knuckle or arch at the level of sternal angle (angle of Louis). Sometimes age-related calcification may be noted at this site. The arch of aorta passes above the left bronchus and to

THE THORACIC AORTA

Flow chart 7.5: Dural sinuses

The paired cavernous sinuses receive venous drainage from the orbits through the superior and inferior ophthalmic veins. The jugular bulbs communicate with the cavernous sinuses by

means of the paired inferior petrosal sinuses. The inferior petrosal sinuses also interconnect with those on the opposite side through a clival venous plexus.


Fig. 7.15: Outline of the thoracic aorta on chest X-ray—PA view. (A) Ascending thoracic aorta curves upwards and at the level of sternal angle continues as arch of aorta; (B) Arch of aorta curves above the left main bronchus and descends into posterior mediastinum. It gives off the: 1. Brachiocephalic trunk; 2. Left common carotid artery; 3. Left subclavian artery; (C) At the level of 4th thoracic vertebra, the arch of aorta becomes the descending thoracic aorta; (D) Descending thoracic aorta in posterior mediastinum enters the abdominal cavity through the aortic hiatus (12th dorsal vertebra level)

Fig. 7.16: Angiogram showing the thoracic aorta

Angiograms 81

ABDOMINAL AORTA

The abdominal aorta is the continuation of the thoracic aorta below the diaphragm at T12 vertebral level. In the abdomen aorta is retroperitoneal in its course and travels downwards to its bifurcation at the level of L4 vertebral body. The abdominal aorta supplies the viscera, peritoneum, gonads and spine during its course. Its anterior branches are the celiac arterial trunk, superior mesenteric artery, inferior mesenteric artery (Fig. 7.17). Its lateral branches are inferior phrenic artery, suprarenal arteries, gonadal arteries, lumbar arteries. Its terminal branches at L4 vertebral level are the common iliac arteries and the median sacral artery (Flow chart 7.7).

CELIAC TRUNK

The celiac trunk is the main vascular supply of the foregut supplying the lower part of the esophagus to the duodenum; it also supplies the liver, pancreas and spleen. The celiac trunk arises at the level of T12 vertebra from the abdominal

aorta and courses forwards until the upper border of pancreas and terminates into: the left gastric artery, splenic artery, common hepatic artery (Fig. 7.18). The left gastric artery gives off esophageal branches, then courses to the right along the lesser curvature of stomach and gives of branches to the stomach. The splenic artery courses to the left, is tortuous and runs in the splenorenal ligament to the hilum of the spleen. Before giving off terminal splenic branches it gives off 6-7 short gastric arteries which course in gastrosplenic ligament and the left gastroepiploic artery (which supplies the stomach and omentum).The splenic artery also gives off the posterior gastric artery during its course to splenic hilum. The common hepatic artery courses over the upper border of the pancreas, the main branches are: right gastric artery, gastroduodenal artery, small supraduodenal arteries and terminal branch—The hepatic artery. The right gastric artery runs forwards in the lesser omentum and to the left in lesser curvature of stomach to anastomose with the left gastric artery. The gastroduodenal artery passes behind the 1st part of duodenum

ABDOMINAL ANGIOGRAPHY

Flow chart 7.6: Thoracic aorta

the left of trachea and esophagus. At the level of 4th thoracic vertebra the arch of aorta courses downwards as the descending thoracic aorta in the posterior mediastinum. The descending thoracic aorta gives off post-erior intercostal arteries, 9 in number on either

side. These intercostal arteries pass laterally into the intercostal spaces. At the level of the aortic hiatus in diaphragm (at 12th thoracic vertebra), the descending aorta passes into the abdominal cavity and continues in the abdomen as the abdominal aorta.


and at the lower border of duodenum divides into the right gastroepiploic artery and superior pancreaticoduodenal arteries. The supraduodenal arteries are smaller branches arise from the

common hepatic artery. The common hepatic artery at the porta hepatis divides into the right and left hepatic arteries to supply the liver (Flow chart 7.8).

Fig. 7.17: Angiogram of abdominal aorta

Flow chart 7.7: Abdominal aorta branches

Angiograms 83

Fig. 7.18: Angiogram of celiac arterial trunk

Flow chart 7.8: Celiac arterial trunk (artery of foregut)

SUPERIOR MESENTERIC ARTERY

The superior mesenteric artery is the artery of midgut and supplies the gut from the bile duct entrance to the splenic flexure of colon. This

artery arises from the abdominal aorta at the level of lower border of L1 vertebra. It courses behind the body of pancreas, later it lies anterior to the left renal vein, uncinate process of pancreas and third part of duodenum. Its main branches are


the inferior pancreaticoduodenal artery, jejunal and ileal branches, ileocolic artery, right colic artery, middle colic artery (Fig. 7.19). The inferior pancreaticoduodenal artery is the first branch of superior mesenteric artery. It further divides into anterior and posterior branches to supply the head of pancreas and adjacent duodenum. The jejunal and ileal branches pass between the two layers of the mesentery and create a network of arteries along the jejunum and ileum to supply the same. The ileocolic artery courses down to the base of mesentery into the right iliac fossa and divides into superior and inferior branches. The superior branch courses along the ascending colon to anastomose with the right colic artery. The inferior branch courses down to the ileocolic junction and gives off the anterior and posterior cecal arteries, an appendicular artery and an ileal artery that anastomoses with the terminal branches of superior mesenteric artery. The right colic artery course downwards into the right infracolic compartment and divides into

the ascending and descending branches. The ascending branch courses along the ascending colon upwards to anastomose with a branch from middle colic artery at hepatic flexure of colon. The descending branch courses downwards along the ascending colon to anastomose with a branch from the ileocolic artery. The middle colic artery arises from the superior mesenteric artery at the lower border of neck of pancreas. It courses into the transverse mesocolon and on the right side of transverse colon divides into two branches – The right and left branches. The right branch anastomoses with the ascending branch of right colic artery. The left branch anastomoses with a branch of the left colic artery (Flow chart 7.9).

INFERIOR MESENTERIC ARTERY

It is also called as the artery of hindgut. It arises as an anterior branch of abdominal aorta at the level of L3 vertebra and courses downwards in lower abdomen. Its branches are the left colic artery,

Fig. 7.19: Angiogram of superior mesenteric artery

Angiograms 85

Flow chart 7.9: Superior mesenteric arteriogram (artery of midgut)

sigmoidal arteries and superior rectal artery. These branches supply the descending colon, sigmoid colon and upper rectum. The marginal artery

Fig. 7.20: Angiogram of right renal artery early arterial phase

of Drummond is formed by an interconnecting anastomotic network of the branches along the mesenteric border of large bowel. The marginal


Fig. 7.22: Angiogram of right renal artery nephrogram phase

Fig. 7.21: Angiogram of right renal artery late arterial phase

Angiograms 87

Fig. 7.23: Angiogram of renal arteries in pyeloureterogram phase

Flow chart 7.10: Renal artery angiogram


ARTERIAL SYSTEM

The axillary artery is the main artery supplying the upper extremity. It is a continuation of the third part of the subclavian artery. The axillary artery begins at the outer border of the first rib and continues until the lower border of teres major muscle (Fig. 7.24). Beyond the teres major muscle the axillary artery continues into the arm as the brachial artery (Flow chart 7.11 and 7.12). The axillary artery for description purposes is subdivided into three parts by the pectoralis minor muscle which crosses middle 1/3rd the axillary artery. The 1st part of axillary is proximal to pectoralis muscle; it gives off the superior thoracic artery. The 2nd part of axillary artery is beneath the pectoralis minor muscle, it gives off the lateral thoracic artery and the thoracoacromial artery. The 3rd part of axillary artery is distal to the pectoralis minor muscle; it gives off the subscapular artery, anterior humeral circumflex artery and the posterior circumflex artery. The brachial artery is continuation of axillary artery in arm. The artery is superficial in its course and lies beneath the deep fascia in the anteromedial aspect of arm. Its branches are: the

profunda brachii artery, middle collateral artery, radial collateral artery, superior ulnar collateral artery, inferior ulnar collateral artery, muscular branches to flexor muscles and nutrient artery to humerus (Figs 7.25 and 7.26). The radial artery originates as a terminal branch of the brachial artery at the cubital fossa. It runs deep to the brachioradialis muscle on the lateral aspect of forearm and at the wrist joint it courses in the anatomical snuff box and forms the deep palmar arch. The radial artery gives small muscular branches in forearm, the radial recurrent artery and a superficial branch near the radiocarpal joint (Flow chart 7.13). The princeps pollicis artery is a branch of radial artery in hand, it divides into two smaller branches that run laterally along the thumb (Figs 7.27 and 7.28). The ulnar artery arises as a terminal branch of the brachial artery at cubital fossa. It courses on the medial aspect of forearm deep to the flexor muscles. The ulnar artery gives off the anterior and posterior ulnar recurrent arteries in proximal forearm and also a few muscular branches along its course in forearm. The ulnar artery passes superficial to the flexor retinaculum at the wrist joint and continues as the superficial palmar arch

UPPER LIMB ANGIOGRAPHY

artery of Drummond is crucial to maintain the vascular supply of large bowel.

RENAL ARTERY

Both the renal arteries arise at right angles to the abdominal aorta at the level of L2 vertebra. The left artery is shorter than the right. Each renal artery gives off small suprarenal and ureteric branches. The renal arteries course behind the pancreas and the renal vein to reach the hilum of the kidney on either side (Figs 7.20 to 7.23). At the hilum the renal artery branches into anterior and posterior divisions. Each kidney is

subdivided into five segments based on arterial supply. The anterior arterial division supplies the apical, upper, middle and lower segments while the posterior arterial division supplies the posterior segment (Flow chart 7.10). There is no collateral circulation between these segmental arteries. The segmental arteries are accompanied by their corres ponding veins. Each segmental artery divides into lobar artery, interlobar artery, arcuate artery and finally into interlobular arteries. The segmental veins communicate with each other and at the hilum they join to form the renal vein. At the hilum of each kidney the structures from front to back are vein, artery and ureter.

Angiograms 89

Fig. 7.24: Angiogram showing subclavian artery and axillary artery

Fig. 7.25: Angiogram showing brachial artery


Fig. 7.26: Angiogram showing radial and ulnar arteries

Fig. 7.27: Angiogram showing ulnar artery and anterior interosseous artery

Angiograms 91

Fig. 7.28: Angiogram showing superficial palmar arch

in the hand. A deep branch of the ulnar artery in hand anastomoses with the deep palmar arch to maintain collateral circulation. The common interosseous artery is a branch of the ulnar artery close to cubital fossa. It divides into the anterior and posterior interosseous branches distal to the radial tubercle and supplies the muscles of the forearm (Figs 7.27 and 7.28). The superficial palmar arch is a direct conti-nuation of the ulnar artery in the hand, it is joined on its lateral side by the superficial branch of radial artery to complete the superficial palmar arch. The deep palmar arch is a direct continuation of the radial artery, it is joined on its medial side by the deep branch of ulnar artery to complete the deep palmar arch (Fig. 7.29). The dorsal carpal arch is formed by both the radial and ulnar arteries within the fascia on dorsum of hand.

Venous System

The veins of the upper extremity can be classified into the superficial veins and the deep veins. The superficial veins are digital veins, metacarpal veins, cephalic veins, basilic vein and median vein. The deep veins are the venae comitantes of radial and ulnar arteries, volar arches of hand, brachial vein, axillary vein and subclavian vein.

Superficial Veins

The digital veins are subclassified into dorsal and volar digital veins. The dorsal digital veins pass along the sides of the fingers and are joined to one another by oblique communicating branches. They have an ulnar and radial network of veins on either side. A communicating branch frequently connects the dorsal venous network with the cephalic vein about the middle of the forearm. The volar digital veins on each finger are connected to


Fig. 7.29: Angiogram showing deep palmar arch

the dorsal digital veins by oblique intercapitular veins. These volar digital veins drain into a venous plexus which is situated across the front of the wrist. The dorsal digital veins from the adjacent sides of the fingers unite to form three dorsal metacarpal veins. They have an ulnar and radial network of veins on either side. The radial part of the venous network is continued into the forearm as the cephalic vein. The ulnar part of the network is continued into forearm as the basilic vein. The cephalic vein continues from the radial part of the dorsal venous network. It runs along the radial border of the forearm. The cephalic vein then ascends in front of the elbow in the groove between the brachioradialis and the biceps brachii muscles. In the upper third of the arm it passes between the pectoralis major muscle and deltoid muscle. It pierces the coracoclavicular fascia and joins the axillary vein just below the clavicle.

The basilic vein is formed from the ulnar part of the dorsal venous network. It travels along the ulnar side of the forearm and in the arm it lies along the medial border of the biceps brachii muscle. It perforates the deep fascia in the middle of the arm and continues on the medial side of the brachial artery to the lower border of the teres major muscle, it then courses in the axilla as the axillary vein. The median antibrachial vein drains the venous plexus on the volar surface of the hand. It travels on the ulnar side of the front of the forearm and joins with the basilic vein.

Deep Veins

The deep veins of the hand are the common volar digital veins, volar metacarpal veins, dorsal meta carpal veins. They unite in the hand to join the radial veins and the superficial veins at the dorsum of the wrist (Flow chart 7.14).

Angiograms 93

Flow chart 7.11: Axillary artery

Flow chart 7.12: Brachial artery

The venae comitantes of the radial and ulnar are the deep veins of the forearm, they unite in front of the elbow to form the brachial veins. The brachial veins are placed one on either side of the brachial artery, receiving tributaries corresponding with the branches given off from that vessel; near the lower margin of the subscapularis muscle, they join the axillary vein. The deep veins have numerous anastomoses, not only with each other, but also with the superficial veins. The axillary vein it begins at the lower border of the teres major muscle, as the continuation of

the basilic vein and ends at the outer border of the first rib as the subclavian vein. At the lower border of the subscapularis muscle it receives the brachial veins. The cephalic vein joins the axillary vein close to its termination. The subclavian vein is the continuation of the axillary vein, extends from the outer border of the first rib to the sternal end of the clavicle, where it unites with the internal jugular to form the innominate vein. It usually has a pair of valves, which are situated around 2.5 cm from its termination.


Flow chart 7.13: Radial artery and ulnar artery

Flow chart 7.14: Upper limb venous system

Angiograms 95

ARTERIESThe abdominal aorta divides into a pair of common iliac arteries at the level of the last lumbar vertebra. The common iliac arteries then divide into inter nal iliac and external iliac arteries (Fig. 7.30). The external iliac artery descends along the medial bor der of psoas major muscle and at the midinguinal point enters the thigh region. The midinguinal point is a point midway between the anterior superior iliac spine and the symphysis pubis (Flow chart 7.15). The common femoral artery is the direct conti nuation of the external iliac artery in the

thigh. The common femoral artery lies medial to the common femoral vein in femoral canal and in upper thigh region gives off the deep profunda femoris artery which is the major artery of the thigh. The other small branches of common femoral artery are the superficial circumflex iliac artery, superficial epigas tric artery, superficial external pudendal artery (Flow chart 7.16) and the deep external pudendal artery (Fig. 7.31). The profunda femoris artery gives off the medial circumflex femoral artery, lateral femoral circumflex femoral artery and four small perforating branches to muscles. The medial

LOWER LIMB ANGIOGRAPHY

Fig. 7.30: Angiography of lower limb (abdominal aorta at its bifurcation)


Flow chart 7.15: Lower limb arterial system

Flow chart 7.16: Superficial femoral artery and profunda femoris artery

circumflex artery gives off the ascending and descending branches and a horizontal branch. The lateral circumflex femoral artery gives off the ascending and descending branches and a transverse branch (Fig. 7.32). The superficial femoral artery is a direct conti-nuation of the common femoral artery in the mid and lower thigh region and accompanies the superficial femoral vein. The superficial femoral artery descends on the medial side of thigh and enters the adductor canal (Fig. 7.33). The popliteal artery is the continuation of superficial femoral artery after exiting the adductor hiatus in popliteal fossa. It gives off the muscular branches – two sural branches and five genicular branches. The genicular branches are superior and inferior lateral branches, superior and inferior medial branches and single

Angiograms 97

Fig. 7.31: Angiography of lower limb (external iliac and common iliac artery)

Flow chart 7.17: Popliteal artery


middle branch. These genicular branches form anastomoses around the knee joint (Flow chart 7.17). The popliteal artery divides into a smaller branch—the anterior tibial artery and the larger branch is the posterior tibial artery (Fig. 7.34). The anterior tibial artery is a branch of popliteal artery. In the leg the anterior tibial artery enters the extensor compartment near the upper border of interosseous membrane and courses downwards towards the ankle. At the ankle, the anterior tibial artery continues as the dorsalis pedis artery of the foot (Figs 7.34 to 7.37). The posterior tibial artery is considered as a direct continuation of the popliteal artery and it enters the posterior compartment of leg and courses downwards. Behind the medial malleolus the post erior tibial artery divides into medial and lateral plantar arteries. The dorsalis pedis artery runs forwards to the base of first intermetatarsal space and passes

down into the sole, where it joins the lateral plantar artery to complete the plantar arch. The first dorsal metatarsal artery is a branch of the dorsalis pedis artery before it enters the sole.

VENOUS ANATOMY

The veins are classified into three systems—The deep veins, superficial veins and perforator veins. The superficial veins are the great saphenous vein, short saphenous vein.The deep veins are femoral vein, popliteal vein, anterior tibial vein, posterior tibial veins and peroneal vein. The perforator veins are the veins connecting the superficial veins with deep veins and contain valves in their walls to prevent backflow of blood and assist in maintaining the superficial-to-deep direction of the blood flow. The great saphenous vein is a large superficial vein of the lower extremity. It originates from the dorsal venous arch of the foot. It courses

Fig. 7.32: Angiography of lower limb (external iliac and common iliac artery)

Angiograms 99

Fig. 7.33: Angiography of lower limb (superficial femoral artery)

upwards anterior to the medial malleolus and continues on the medial side of leg. At the knee, the great saphenous vein lies over the posterior border of medial epicondyle of femur. The great saphenous vein travels medially in lower thigh and then courses anteriorly in upper thigh to pierce the fascia lata; this opening is called the saphenous opening. The great saphenous vein joins the femoral vein, this junction is called the saphenofemoral junction. The tributaries of the great saphenous vein are many, at the ankle it receives the medial marginal vein, it also communicates with the small saphenous vein, the femoral vein, anterior and posterior tibial

veins. In the upper thigh the great saphenous vein receives the tributaries from superficial epigastric, superficial iliac circumflex and superficial external pudendal vein (Flow chart 7.18). The small saphenous vein is a superficial vein in posterior leg. It originates from the lateral end of dorsal venous arch. It courses posterior to the lateral malleolus and continues upwards on the lateral aspect of leg. It passes between the heads of gastrocnemius muscle and drains into the popliteal vein at the knee. The superficial femoral vein is a part of the deep venous system of lower extremity. As the popliteal vein exits the adductor canal and enters the thigh


Fig. 7.34: Angiography of lower limb (popliteal artery)

Fig. 7.35: Angiography of lower limb (popliteal artery at bifurcation)

Angiograms 101

Fig. 7.36: Angiography of lower limb (tibial and peroneal arteries)

Fig. 7.37: Angiography of lower limb (capillary phase in leg)


Flow chart 7.18: Lower limb venous system

region it becomes the superficial femoral vein. The superficial femoral vein receives profunda femoris vein in upper thigh region and becomes the common femoral vein. At the saphenofemoral junction, the common femoral vein receives the great saphenous vein. The popliteal vein lies alongside the popliteal artery in popliteal fossa. It originates by the unification of the anterior and posterior tibial veins in popliteal fossa. Its tributaries in the popliteal fossa are the peroneal vein and short saphenous vein. The popliteal vein enters into the adductor canal and enters into the thigh as the superficial femoral vein. The anterior tibial vein drains the anterior compartment of leg and dorsum of foot. The

anterior tibial vein courses upwards alongside the anterior tibial artery and pierces the interosseous membrane to enter the popliteal fossa and unites with the posterior tibial veins to form the popliteal vein. The posterior tibial vein drains the posterior compartment of leg and plantar surface of foot. It courses upwards to enter the popliteal fossa and unites with the anterior tibial veins to form the popliteal vein. The posterior tibial veins are accompanied by the posterior tibial arteries along its course in leg. The peroneal veins, also known as venae comitantes, are the accompanying veins of the peroneal artery of leg. The peroneal veins course upwards and join the popliteal vein.

The esophagus is a hollow muscular tube; it is 25 cm in length. The esophagus begins at the lower border of cricoid cartilage at the level of C6 vertebra. For descriptive purposes the esophagus has a cervical segment, thoracic segment and intrabdominal seg ment. The cervical segment of esophagus is in the midline posterior to the trachea, it courses to the left as it enters the thoracic cavity. The thoracic segment of esophagus courses to midline between the 5th to 7th thoracic vertebral level, further down in the thoracic cavity the esophagus lies to the left of midline. The esophageal opening in the left hemidiaphragm is at the level of 10th thoracic vertebra. The intraabdominal segment of esophagus is short in length, around 1-2 cm and enters the stomach. In passive state the esophagus is collapsed, it distends when a bolus of food or water passes through its lumen. During barium swallow exa minations observe the peristaltic waves on fluoro scopy propagating the barium bolus into the stomach below. At the distal end of esophagus is the lower esophageal sphincter, it helps to maintain the tone of the esophagus preventing gastric reflux and at the same time provides support to the esophagus by acting as a support sling to the diaphragm. If there is failure of the lower esophageal sphincter to relax the esophagus dilates and food contents

may be visible on X-ray films as air-fluid levels. One must keep in mind the normal anatomical narrowing of the esophagus at the following sites: (i) The cricopharyngeal sphincter in cervical segment, at origin of esophagus, around 15 cm from incisor teeth (ii) At the level of aortic arch, around 22 cm from incisor teeth (iii) The left bronchus crosses in front of esophagus, around 27 cm from incisor teeth (iv) the esophageal opening in diaphragm, around 38 cm from the incisor teeth. It is a upper gastrointestinal (GI) radiological study using high density barium contrast media (250%). Two to three table spoon scoops are given orally and the upper GI is visualized on fluoroscopy. A control film is necessary if perforation is suspected; water-soluble contrast such as gastrograffin is given orally instead of barium. In routine studies, no special patient preparation is required, after the patient swallows the barium contrast in erect position and spot films are taken under fluoroscopic guidance. The column of barium contrast is followed on fluoroscopy as the barium passes in the oropharynx into the esophagus and finally into the stomach. Normally the spot films of upper cervical region with esophagus is covered in posteroanterior (PA), lateral and right antero-roblique (RAO) views. The spot films of lower

BARIUM SWALLOW

Radiological ProceduresC H A P T E R

8


esophagus with gastroesophageal junction are covered in posteroanterior (PA), lateral and right antero-oblique (RAO) views. Special views

in Trendelendburg position may be needed to demonstrate hiatus hernia. No special aftercare is required for this procedure (Figs 8.1 to 8.3).

Fig. 8.1: Barium swallow study (upper gastrointestinal tract—lateral view)

Fig. 8.2A

A

Radiological Procedures 105

Fig. 8.3: Barium swallow study (upper gastrointestinal tract—right antero-oblique view)

Fig. 8.4B

Figs 8.2A and B: Barium swallow study (upper gastrointestinal tract posteroanterior view)

B


The stomach is a muscular structure that distends when filled with barium contrast on barium meal follow-through study. At its proximal end is the gastroesophageal junction, to the left of midline. The main parts of stomach are the cardia, fundus, body and pyloric portion (Fig. 8.4). The cardia refers to the portion of stomach at the gastroesophageal junction, it is located to the left of midline, at 10 thoracic vertebral level, it is around 40 cm from the incisor teeth. The fundus is the portion of stomach which lies above the level of cardia and usually filled with air, as seen on plain X-ray abdomen. The body of stomach has two curvatures—The greater curvature and the lesser curvature. There is a small notch in the

lower part of lesser curvature; this notch is called incisura angularis. The pylorus of stomach is the portion which lies beyond the incisura angularis, it has two subportions—The proximal portion is called the pyloric antrum and the distal portion is called the pyloric canal. The pyloric canal lies anterior to the head and neck of pancreas. The gastroduodenal junction lies to the right of midline at L1 vertebral level, the pyloric sphincter is a thickened section of the pyloric canal at the gastroduodenal junction (Fig. 8.5). The duodenum is a loop of bowel that connects the stomach to the jejunum. The duodenum begins at L1 vertebral level to the right of midline at the gastroduodenal junction. The curved loop

BARIUM MEAL FOLLOW-THROUGH (BMFT)

Fig. 8.4: BMFT study erect posteroanterior (PA) view of stomach with duodenal cap


Fig. 8.5: BMFT study erect right antero-oblique (RAO) view of stomach with duodenal cap

Fig. 8.6: BMFT study erect left antero-oblique (LAO) view of stomach with duodenum


of duo denum (Fig. 8.6) is for descriptive purposes has four parts—1st, 2nd, 3rd and 4th parts. The 1st part of duodenum has a short horizontal course, the duodenal cap is located in this portion. The 2nd part of duodenum is a vertical portion that runs downwards to the right of midline. The 2nd part of duodenum has an opening in its posteromedial wall approximately 10 cm from pylorus, called the ampulla of Vater. The ampulla of Vater receives the common bile duct and the main pancreatic duct. The 3rd part of duodenum is horizontal in its course, it lies anterior to the right psoas muscle and crosses the midline to lie anterior to the left psoas muscle. The jejunal loops of bowel lies anterior to the 3rd part of duodenum. The 4th part of duodenum is the short ascending loop of duodenum which lies to the left of aorta and anterior to the left psoas muscle. The duodenum

joins with the jejunal loops at the duodenojejunal flexure, this flexure is fixed to the left psoas fascia by fibrous tissue. The small bowel is approximately 4 to 6 meters in length. The jejunum is the proximal 2/5th of small bowel, has thicker walls and its lumen is wider as compared to the ileum. On barium studies the jejunum has a feathery appearance due to its mucosal pattern. The ileal loops form the remaining 3/5th of small bowel; have a featureless pattern on barium studies. The lumen of ileal loops progressively becomes narrower distally as they approach the cecum, at the ileocecal junction (Figs 8.7 to 8.10). Barium meal follow-through is a radiographic contrast study of the gastrointestinal tract from the stomach to the terminal ileum. It gives valuable information of stomach, jejunum and ileum to

Fig. 8.7: BMFT study—Supine posteroanterior (PA) view of stomach with ileal loops


Fig. 8.8: BMFT study—Supine posteroanterior (PA) view of ileal loops with cecum

Fig. 8.9: BMFT study—Supine right antero-oblique (RAO) view of terminal ileum with ascending colon


Fig. 8.10: BMFT study—Supine right antero-oblique (RAO) view of ileocecal junction

assist in detecting various pathologies. Plain radiograph of the abdomen is normally taken as control film before starting the barium study. Single contrast method is commonly used, 300 ml of high density barium 100 percent is given orally and the barium column is followed on fluoroscopy and spot films taken. Less commonly used barium techniques involve using effervescent agents with barium to demonstrate mucosal pattern. In cases of suspected perforation barium is contraindicated, water-soluble, nonionic contrast like gastrograffin is used. BMFT study is contraindicated in cases of complete obstruction of small bowel. Patient is kept nil orally 6-8 hours before start of study. Metoclopramide 20 mg can be given orally 20 minutes before the BMFT study to slightly increase bowel peristalsis. During the BMFT study, compression pad techniques

may be used to displace overlying bowel loops to visualize the ileocecal junction and terminal ileum. In double contrast barium meal study, the barium is followed by asking the patient to ingest a sachet of powder, like ENO antacid. The patient is asked to roll and this allows the gas produced to distend the mucosal folds of stomach and mucosal patterns can be studied on fluoroscopy. After the procedure the patient should be told that bowel motion may appear white in color for a few days and advised to have a good intake of water to avoid barium impaction. Some complications of BMFT study includes-aspiration of barium during the procedure, barium can worsen appendicitis, barium can couvert a partial bowel obstruction into a total obstruction due to barium impaction, leakage from unsuspected perforation may lead to barium peritonitis.


The anal canal is around 4 cm in length; it is the terminal end of gastrointestinal tract. At its distal end is the anal opening in the perineum. The proximal end of anal canal is the anorectal junction, here the puborectalis muscle fibers on either side of the perineum act as a sling around this junction and provide support. The tone of the anal canal is maintained by the internal and external sphincters. The rectum is around 10 to 12 cm in length (Fig. 8.11). It begins at the level of the 3rd sacral vertebra; the proximal end of rectum is continuous with the sigmoid colon above, while the distal end of rectum terminates at the anorectal junction below. The presacral space lies behind the rectum. In males the rectovesical space is anterior to rectum, while in females the rectouterine pouch is anterior to the rectum (Fig. 8.12).

The sigmoid colon is around 40-45 cm in length. It is a part of the large bowel located from the level of the pelvic brim proximally to the rectosigmoid junction at the level of S3 vertebra. The sigmoid colon has its own mesentery, called as the sigmoid mesocolon. Due to this sigmoid mesocolon the sigmoid colon is more mobile and can rotate around its mesenteric axis and can lead to volvulus and strangulation. The descending colon is located on the left side of abdomen. It is about 30-35 cm in length and extends from the splenic flexure (level of 10th rib on left side) proximally to the pelvic brim distally. The transverse colon is around 40-45 cm in length. It extends from the hepatic flexure to the splenic flexure crossing the midline. The splenic flexure is normally at a bit higher level

BARIUM EnEMA

Fig. 8.11: Barium enema study—Left lateral view (rectum and sigmoid colon)


Fig. 8.12: Barium enema study—Supine view (ascending, transverse, descending colon)

than the hepatic flexure. The ascending colon extends upwards from the ileocecal junction to the hepatic flexure. It is around 15 cm in length and lies on the right side of abdomen and lies over the lumbar fascia and iliac fascia. Haustra are hallmarks of large bowel and are due to the taenia coli longitudinal muscles. The cecum is a blind pouch situated between the ileocecal junction and the ascending colon in the right lower abdomen, overlying the iliopsoas fascia. The cecum has its own mesentery, thus giving the cecum some mobility. In some cases, there may be two folds of peritoneum on either sides of posterior cecal wall forming the retrocecal recess. The appendix may be occasionally located in this retrocecal recess. The ileocecal junction is located on the medial side of cecum, it has valves that prevent reflux of large bowel contents into the ileum. The appendix is a blind ended structure which opens usually on the posteromedial side of cecum. During barium

meal follow-through examinations, the lumen of appendix might be seen as a small structure adjoining the cecum. The appendix is around 7 to 8 cm in length, it has a short mesentery called the mesoappendix. The appendicular artery travels in the mesoappendix, in cases of appendicitis the appendicular artery is ligated in the mesoappendix (Fig. 8.12). It is a radiological procedure carried out with the use of barium as contrast to visualize the lower gastrointestinal tract for any pathology. Some indi cations are change in bowel habit, obstruction, melena, anemia, mass, lower gastrointestinal pain. Patient preparation includes low residue diet three days prior to the procedure, intake of plenty of fluids, laxative taken the night before the procedure. In the single contrast method, the barium is infused through a rubber catheter place in rectum. Intermittent screening is done under fluoroscopy and spot films taken. Barium is infused until the top of barium column


reaches the hepatic flexure. Barium is inert substance and reactions to it hardly ever occur, but certain conditions are contraindicated for barium enema. Barium enema is contraindicated in toxic megacolon, pseudomembranous colitis, postrectal biopsy, bowel perforation. Nonionic contrast media is used in cases of perforation.

After the barium enema procedure is completed, advice the patient that the stools would be white for a few days, to take plenty of fluids orally and laxatives may be prescribed. Venous extravasation of barium is a rare but known complication of barium enema study, it may result in barium pulmonary embolism.

InTRAVEnOUS UROGRAM

It is a radiological procedure to investigate the kidneys, ureter and bladder by injecting a nonionic water-soluble contrast media intravenously. Patient preparation includes nil per orally for at least 8 hours but patient should not be dehydrated, oral laxatives are usually prescribed to take the night before the procedure. Serum creatinine and blood urea nitrogen tests are done to evaluate if contrast can be safely administered. Patient may have allergic reaction to the contrast media and all emergency drugs and equipment should be ready before contrast is injected. In infants and children the radiation dose should be minimized.Pregnancy is a contraindication for this procedure. Plain X-ray KUB control film AP taken in supine position (Fig. 8.13), check for good bowel preparation, outline of both renal kidneys, psoas muscle outlines, bony pelvis, also look for any abnormal calcific densities for example in the renal areas and bladder. It is important to ask the patient to void before taking the plain X-ray KUB film and make sure the plain KUB film covers the diaphragms above to the pubis below. Normally, a portion of each upper renal pole usually extends above the 12th rib, with the right kidney normally slightly lower than the left due to the position of the liver. Each kidney normally measures around 12 cm × 6 cm × 3 cm, kidneys lies in the retroperitoneal region, the hilum of each kidney lies over the psoas muscle, the outer convexity of each kidney lies on the aponeurosis of transversus abdominis muscle. The vertical axis of the kidney lies parallel the upper one-third of the psoas muscle, due to this slight

rotation the width of each kidney appears slightly reduced on supine AP X-ray films. Compression band around the lower abdomen is applied so that the ureters are compressed against the sacral ala, this helps to concentrate the contrast media in the kidneys and upper ureter. Compression band is avoided in children, abdominal trauma, large abdominal mass and postoperative cases. A test dose of intravenous contrast around 2-3 ml is given and look for any reaction like nausea, dizziness, breathlessness, contrast extravasation from displaced cannula. If the patient is comfortable then proceed to give the rest of dose carefully. IVU films in supine position (AP) is taken at 5 minutes, to demonstrate the nephropyelogram phase (Fig. 8.14). Subsequent films are taken at 15 minutes, 30 minutes (Figs 8.15 and 8.16). At the release of compression band, the bolus of contrast media in urine enters the ureters to be visualized throughout their length. Also segmental nonvisualization of the ureter due to peristalsis can be overcome with compression release, and the entire ureter, is filled with contrast laden urine from the ureteropelvic junction to the ureterovesical junction. Full bladder film is then taken followed by postvoid supine film (Fig. 8.17). During the course of this procedure note whether-both kidneys concentrate and excrete the contrast, pelvicalyceal systems are not dilated, the course and caliber of the ureters, any intravesical mass or filling defects (Fig. 8.18). The appearance of the renal pelvicalyceal system


Fig. 8.13: X-ray KUB region (Plain film)

Fig. 8.14: IVU film at 5 minutes (nephropyelogram)


Fig. 8.15: IVU film at 15 minutes (right lower ureter visualized)

Fig. 8.16: IVU film at 30 minutes (left midureter visualized)


Fig. 8.17: IVU film at 40 minutes (left lower ureter visualized)

Fig. 8.18: IVU film at 50 minutes (full bladder)


should be examined closely because intravenous urography is the most accurate imaging modality for visualizing the urothelium-lined surfaces and evaluating potential abnormalities. The ureter usually begins as a smooth extension from the renal pelvis adjacent to the lateral margin of the psoas muscle. At about the L3 level, the ureter passes to anterior to the psoas muscle, crossing it from lateral to medial side. The proximal ureteric

course is retroperitoneal passes along the outer half of the transverse processes of the upper lumbar vertebra (L1 to L3). The midureteric portion of ureter crosses anterior to the iliac vessels at a higher position on the right than on the left and courses downwards. Once within the anatomic pelvis, the distal ureter lies parallel to the inner margin of the iliac bone until it enters the bladder at the ureterovesical junction.

MICTURATInG CYSTOURETHROGRAM

The bladder is a hollow muscular organ in the pelvic cavity. It has a rounded appearance with smooth margins when distended with contrast. The ureters insert into the bladder base on the posterior surface. The area between the opening of the two ureters on either side and the internal urethral opening inferiorly at bladder neck is called the trigone of bladder. The bladder neck is surrounded by smooth muscle fibers, also called as the internal urethral sphincter. The urethra begins inferiorly at the bladder neck and courses downwards to open into the external urethral meatus. In males the urethra is around 18 cm in length, and for descriptive purposes divided into anterior urethra and posterior urethra. The posterior urethra has two segments the more proximal segment is called the prostatic segment, while the distal segment which lies close to the perineal membrane is called the membranous segment. The prostatic segment (3-4 cm in length), it runs through the prostate downwards, the proximal part of prostatic urethra is also known as preprostatic part and it is surrounded by smooth muscles of the bladder neck. This smooth muscle encasing the preprostatic part contracts during ejaculation to prevent seminal reflux into the urinary bladder. The membranous urethra is the segment of posterior urethra is around 1.5 cm in length and it traverses the perineal membrane. The membranous urethra

is the narrowest part of the male urethra; it is prone to strictures and obstruction. External urethral sphincter (sphincter urethrae) consist of smooth muscle fibers that extend from the lower part of prostatic urethra to the region just above the perineal membrane. The anterior urethra is about 15 cm in length and has two segments. After exiting from the perineal membrane the anterior urethra has a smooth dilated proximal segment, this segment is called the bulbar segment. The anterior urethra curves forwards and runs inside the penis, this distal segment of anterior urethra is called the penile segment. At the external meatus the urethra is narrower as compared to the rest of penile urethra. In females the urethra is shorter around 4-5 cm in length, so urinary tract infections are much more common in females. Micturating cystourethrogram is a radiological procedure to demonstrate the radiological anatomy of the urinary bladder and urethra during the micturation process (Figs 8.19 to 8.22). Some indications for this procedure include vesicoureteric reflux, to look for any abnormalities of the bladder, stricture or fistulas of urethra, posterior urethral valves. Relative contraindication includes acute urinary tract infection. To begin with, the patient’s urinary bladder is first catheterized by a plain rubber catheter and nonionic water-soluble contrast media (around 250–300 ml) is instilled into


Fig. 8.19: Micturating cystourethrogram—Anteroposterior view (standing) with urinary catheter in the bladder

Fig. 8.20: Micturating cystourethrogram—Left oblique view (standing)


Fig. 8.21: Micturating cystourethrogram—Right oblique view 30o (standing)

Fig. 8.22: Micturating cystourethrogram—Right oblique view 45o (standing)

the bladder. On fluoroscopy, the bladder with contrast is identified, its smooth outer margins should be distinct: Spot anteroposterior view is taken. Next, the rubber catheter is removed from

bladder and the patient is asked to micturate here; the anatomy of the urethra is observed on fluoroscopy. Adults usually find it easier to micturate in standing or squatting position,


while children are comfortable to micturate in supine position. Spot films in right anterooblique and left anterooblique are taken to demonstrate the urethra in males. In females anteroposterior view is usually sufficient to demonstrate the urethra. If the contrast is observed in the ureters

then full length abdominal film is required to visualize the kidneys to demonstrate the reflux. Some complications of this procedure include temporary dysuria, transient hematuria, bladder perforation, acute urinary tract infection, adverse reaction to contrast.

RETROGRADE URETHROGRAM

The anterior urethra is 15 cm in length, it has two segments, the proximal segment is called the bulbar segment; the distal segment is called the penile segment. Fossa navicularis is a small dilated part of penile urethra near the external urethral meatus. When passing the cannula into the external urethral meatus the tip of the cannula should be directed downwards towards the floor of fossa navicularis, otherwise injury to

the urethra can occur resulting in a false passage likely through the large roof of fossa navicularis. Retrograde urethrogram (RGU) is a radiological procedure to evaluate the anterior urethra in males by injecting a bolus of water-soluble contrast through a cannula into the external urethral meatus (Fig. 8.23). Some indications for this procedure include stricture, urethral tear, congenital abnormalities, fistulae.

Fig. 8.23: Retrograde urethrogram right antero-oblique view


The patient does not need any special prior preparation before procedure, but the patient should empty his bladder before the procedure is started. The urethra is opacified and any narrowing or obstruction to the flow of contrast is identified. The patient is asked to lie down supine on the X-ray table (Bucky table) and 30o left anterior oblique view is taken when the contrast is injected. The position of the patient in supine position is important, the hip

is abducted and the knee is flexed, the pelvis is slightly tilted to the same side so that the anterior urethra does not overlap with the femur. Spillage of contrast into the urinary bladder is noted. Contraindications for this procedure are acute urinary tract infection and recent cystoscopy. Ideally the retrograde urethrogram should be followed by micturating urethrogram to evaluate the posterior urethra. No special aftercare is needed after the procedure.

The female internal genitalia consist of the uterus, fallopian tubes and ovaries. The uterus is a muscular pear-shaped structure, nongravid uterus measures around 80 mm × 50 mm × 30 mm approximately. The uterus comprises of a fundus, body and cervix. The fundal portion of uterus lies above the opening of the fallopian tube on either side. The body of uterus lies below the opening of the fallopian tubes. The upper end of body of uterus has a narrow angle, it is called the cornual end where the fallopian tube opens into the uterine cavity. The body of uterus gradually tapers downwards to form the cervix (Figs 8.24 and 8.25). The cervix has two parts; the upper part which lies above the vagina is called the supravaginal portion. The lower part of cervix which protrudes into the vagina is called the vaginal portion of cervix and has an anterior lip and posterior lip visible using a Sim’s speculum. The upper end of cervical canal is called the internal os; the lower end of cervical canal is called the external os. Normally the external os lies at the level of ischial spines. There are two fallopian tubes, each uterine tube is approximately around 10 cm in length. The fallopian tube for descriptive purpose is subdivided into the intramural part, isthmus, ampulla and infundibulum. The intramural portion of fallopian tube is the most medial

portion which lies in the muscular part of uterus. The isthmus portion lies adjacent to the uterus, it is the most narrow portion of fallopian tube. The ampulla is the lateral portion of the fallopian tube, it is more wider as compared to the isthmus. The infundibular portion of fallopian tube is the lateral end of fallopian tube, it has finger-like projections called fimbriae and connect it to the ovary. The ovary is ovoid structure one on either side in the parametrium, measuring around 30 mm × 20 mm × 10 mm. The ovary size is smaller in premenarchal and postmenopausal age groups. The upper pole of each ovary is tilted towards the infundibular portion of each fallopian tube. The location of ovary changes during pregnancy and usually never returns to its original position. The vagina is a hollow muscular structure, at its upper end the cervix projects into it, creating anterior, posterior and two lateral vaginal fornices (Figs 8.26 and 8.27). The lower end of vagina opens into the external genital opening surrounded by labia.

HYSTEROSALPHInGOGRAM

It is a radiological procedure where nonionic con trast is injected into the uterus. Spillage from the fallopian tubes into the peritoneal cavity is observed on fluoroscopy and spot films are taken

RADIOLOGICAL AnATOMY OF FEMALE REPRODUCTIVE ORGAnS


Fig. 8.24: Hysterosalpingogram

Fig. 8.25A

A


Fig. 8.25B

Figs 8.25A and B: Hysterosalpingogram (uterus with both fallopian tubes)

Fig. 8.26: Hysterosalpingogram (fallopian tubes with spillage into peritoneal cavity)

B


Fig. 8.27: Hysterosalpingogram (fallopian tubes with spillage into peritoneal cavity)

(Fig. 8.27) or preferably cine recording is done. Common indications for this procedure are infertility, recurrent miscarriages and previous ectopic pregnancy. Pregnancy is an absolute contraindication. Usually the procedure is done around the 8th to 10th day of the menstrual cycle, as the patient is unlikely to be pregnant during this period, also the cervix would be firm enough to hold the cannula. Normally, the procedure is explained to the patient to make her comfortable and cooperative, and consent form is signed by the patient prior to the procedure. Atropine 1 mg is injected intramuscularly prior to the procedure to counter any vagal response when inserting the cannula into the cervix. The patient is placed supine and the external genitalia and the external cervical os is cleaned with povidone-iodine soaked swab. Any bleeding from the external cervical os is noted at this point of time, if this is present then the procedure is postponed. If there is no bleeding observed from the cervix,

Sim’s speculum is inserted to get a clear view of external cervix os, the anterior lip of cervix is grasped by vulsellum forceps carefully and the cannula (Leech-Wilkinson cannula) is inserted carefully into the cervix until it is firmly in the cervical canal (Fig. 8.24). Non-ionic contrast is injected around 3ml to visualize the uterine cavity and then followed by the rest of contrast (up to 20 ml). Spot films of the uterus and fallopian tubes with spillage into peritoneal cavity are taken (Figs 8.25A and B). Patient might experience some discomfort when the spillage occurs into the peritoneal cavity. After the spot films are exposed and viewed to assess for diagnostic quality (Figs 8.26 and 8.27) and then the cannula is carefully withdrawn from the cervix. Oral analgesics and antibiotics may be prescribed to the patient after the procedure. Hysterosalphingogram is a safe and effective procedure to demonstrate any block in the fallopian tubes and can demonstrate abnormal anatomy of uterine cavity.


DACROCYSTOGRAM

The lacrimal apparatus consists of the lacrimal gland, lacrimal canaliculi, lacrimal sac and the nasolacrimal duct. The lacrimal gland lies in the lacrimal fossa, located on the lateral part of the roof of the orbit. The lacrimal gland secretes clear fluid known as tears which helps to lubricate and protect the cornea and the sclera of the eye. At the medial end of each eyelid on its inner surface is a small punctum which opens directly into the lacrimal canaliculus. The lacrimal canaliculus is a small tubular canal that leads into the lacrimal sac. Excess tears produced by the lacrimal gland are conveyed into the lacrimal sac through the lacrimal canaliculus. The lacrimal sac is a small structure located in the lacrimal groove (Figs 8.28 and 8.29). The lacrimal groove is lies at the

junction of lacrimal bone with the maxillary bone. When the eyelids are wide open the lacrimal punctum and canaliculi are closed, so the tears cannot drain into them, but when the eyes are closed the orbicularis oculi muscle allows the muscle fibers and ligaments around the lacrimal punctum to relax thus allowing the excess tears to drain into the lacrimal sac. The lacrimal sac opens inferiorly into the nasolacrimal duct. The nasolacrimal duct is about 20 to 22 mm in length and it runs downwards and laterally to open into the ipsilateral inferior meatus in the nasal cavity. At the opening of the nasolacrimal duct into the inferior meatus, the mucous membrane of nasal cavity is thrown into folds to act as a valve to prevent air entering into the nasolacrimal duct.

Fig. 8.28: Dacrocystogram—AP view


Fig. 8.29: Dacrocystogram—Right oblique view

Dacrocystogram is a radiological procedure to evaluate the lacrimal sac and nasolacrimal duct with water-soluble contrast media. Patient is placed in supine position and the lacrimal sac is gently massaged to release any collection within it. Next, the lower eyelid is everted to locate on the medial aspect a tiny punctum. This tiny punctum opens into the lower canaliculus, which leads into the lacrimal sac. A lacrimal

punctum dilator is used to carefully dilate the punctum. A syringe with water-soluble contrast is placed into the lacrimal punctum and contrast is injected. The lacrimal canaliculi, sac and the nasolacrimal duct are opacified and observed on fluoroscopy, spot X-rays are taken in AP and oblique positions. Any obstruction to the flow of contrast or abnormally dilated portions is noted during this procedure.

Fig. 9.1: Shoulder joint

Ossification is the first area of a bone which starts to ossify, the point where ossification commences is termed as ossification center. There are two types of ossification centers a) The primary ossification center is the first area of a bone to start ossifying. It appears during prenatal development in the central part of each developing bone. In long bones the primary centers occur in the shaft and in other it occurs usually in the body of the bone. Usually bones

have one primary center as in all long bones. Few bones like hip and vertebrae have multiple primary centers, b) The secondary ossification center is the area of ossification that appears after the primary ossification center, most secondary ossification center appear during the postnatal and adolescent years. Most bones have more than one secondary ossification center. In long bones, the secondary centers appear in the epiphysis (Figs 9.1 to 9.6 and Tables 9.1 to 9.6).

Ossification CentersC H A P T E R

9


Fig. 9.2: Elbow joint

Fig. 9.3: Wrist and hand

Ossification Centers 129

Fig. 9.5: Knee joint

Fig. 9.4: Hip joint


Fig. 9.6: Foot

Table 9.1: Shoulder joint

Bones Ossification

Body of scapula 8th week of fetal life

Body of clavicle (two centers) 5th and 6th week of fetal life

Shaft of humerus 8th week of fetal life

Epiphysis Appearance Fusion

Head of humerus 1 year

Greater tuberosity 3 years

Lesser tuberosity 5 years

Acromion process 15–18 years 25th year

Middle of coracoid process 1 year 15th year

Root of coracoid process 17th years 25th year

Inferior angle of scapula 14–20 years 22–25 years

Medial border of scapula 14–20 years 22–25 years

Medial end of clavicle 18–20 years 25th year

Table 9.2: Elbow joint

Bones Ossification

Radial shaft 8th week of fetal life

Ulnar shaft 8th week of fetal life


Lateral epicondyle 10–12 years 17–18 years

Medial epicondyle 05–08 years 17–18 years

Capitellum 01–03 years 17–18 years

Head of radius 05–06 years 16–19 years

Trochlea 11th year 18th year

Olecranon process 10–13 years 16–20 years

Ossification Centers 131

Table 9.4: Hip joint

Bones Ossification

Proximal femoral shaft 7th week of fetal life


Femoral head 1 year 18–20 years

Greater trochanter 3–5 years 18–20 years

Lesser trochanter 8–14 years 18–20 years

Table 9.3: Wrist and hand

Bones Ossification

Capitate 4 months

Hamate 4 months

Triquetral 3 years

Lunate 4–5 years

Trapezium 6 years

Trapezoid 6 years

Scaphoid 6 years

Pisiform 11 years

Metacarpals 10th week of fetal life

Proximal phalanges 11th week of fetal life

Middle phalanges 12th week of fetal life

Distal phalanges 9th week of fetal life

Middle phalanx of 5th digit 14th week of fetal life


Lower end of radius 1–2 years 20th year

Lower end of ulna 5–8 years 20th year

Metacarpal heads 2.5 years 20th year

Base of proximal phalanges 2.5 years 20th year

Base of middle phalanges 3 years 18–20 years

Base of distal phalanges 3 years 18–20 years

Base of 1st metacarpal 2.5 years 20th year


Table 9.5 Knee joint

Bones Ossification

Tibial shaft 7th week of fetal life

Fibular shaft 8th week of fetal life

Patella 5 years


Proximal tibia At birth 20th year

Tibial tubercle 5–10 years 20th year

Proximal fibular 4th year 25th year

Distal femur At birth 20th year

Table 9.6: Foot

Bones Ossification

Calcaneus 6th month of fetal life

Talus 6th month of fetal life

Navicular 3–4 years

Cuboid At birth

Lateral cuneiform 1 year

Middle cuneiform 3 years

Medial cuneiform 3 years

Metatarsal shafts 8th–9th week of fetal life

Phalangeal shafts 10th week of fetal life


Metatarsals 3 years 17–20 years

Proximal phalangeal base 3 years 17–20 years

Middle phalangeal base 3 years 17–20 years

Distal phalangeal base 5 years 17–20 years

Posterior calcaneal 5 years At puberty

X-rays are invisible, highly penetrating, electro-magnetic radiations having wavelength of 0.1-1 Å and speed is same as that of light (3×108 m/sec). They are considered as a form of modified electrons. X-ray tube is a diode consisting of tungsten filament cathode and a rotating anode target of tungsten held in an evacuated glass. Tungsten anode is inclined at an angle so that it works on line-focus principle. X-rays are produced when the electron beam strikes the anode made of tungsten or molybdenum. Tungsten (atomic number 74) is used as target material for X-ray production. Molybdenum (atomic number 42) is used as the target in mammography. Cathode is connected to the negative terminal and consists of small coil of wire made of tungsten (filament). Cathode generates the electrons from the electric circuit and focuses them into well-defined beam aimed at anode. Anode is relatively large piece of metal that connects to positive end of electric circuit. It converts electronic energy into X-rays and rapidly dissipates heat produced during this process. Anode is made up of tungsten because it has high melting point, low rate of evaporation and maintains strength at high temperature (Fig. 10.1). The electrons are produced by cathode filament by electric current, emitting photoelectrons. The electrons coming from the filament cathode are

then accelerated towards the target anode by a large electrical potential applied between the filament and target. When the beam of electrons hits the target anode there is rapid deceleration of electrons leading to emission of X-rays and heat. About one percent of the energy generated is emitted as X-rays. The rest of the energy is released as heat. The assembly of cathode and anode is enclosed by the envelope which is made of glass. It provides support and electric insulation, keeps cathode and anode in air-tight enclosure and maintains vacuum in tube. Housing is the outermost covering that encloses and supports the envelope. It is filled with oil that provides electric insulation, allows heat dissipation and cooling. Modern X-ray tubes are based on hot cathode tube principle invented by Coolidge in 1913 which enables excellent control of kVp (kilovolt peak) and mAs (milliampere second). kVp is responsible for penetration of X-ray beam, low kVp gives high contrast. mAs is responsible for the film blackening. The radiation intensity on the cathode side of the X-ray tube is higher than on the anode side and this principle is called as the anode Heel effect. The heat generated in the tube is dissipated in three ways: conduction, convection and radiation. Diagnostic X-ray machine uses voltage upto 150 kVp whereas machines used for radiotherapy use high voltage > 200 KVP.

Production of X-raysC H A P T E R

10


Two different interactions give rise to X-rays. An interaction with electron shell produce characteristic X-rays photons, while interaction with atomic nucleus produces Bremsstrahlung X-ray photons. In diagnostic radiology about 85 percent of X-rays arise from Bremsstrahlung radiation and 15 percent from characteristic radiation. X-ray filter made of aluminum absorbs low energy radiation and decreases unnecessary patient exposure and thus improves film contrast.

Grid is made of parallel lead lines with intervening radiolucent material. It absorbs scattered radiation. Cones and collimators restrict field size and decrease scatter. Distance from X-ray tube (focus) to the X-ray film is called focus film distance (FFD). It is 100 cm for usual radiographs of extremities, abdomen and skull. However, for standing radiograph of chest, it is 180 cm (6 ft) so as to reduce the magnification.

Fig. 10.1: Line diagram shows production of X-rays

Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a precontrast image or the mask from later images, hence the term ‘digital subtraction angiography’. Digital subtraction angiography (DSA) is primarily used to image blood vessels. It is useful in the diagnosis and treatment of: Arterial and venous occlusions, carotid artery stenosis, pulmonary embolisms, acute limb ischemia, and arterial stenosis, which is particularly useful for potential renal donors in detecting renal artery stenosis, cerebral aneurysms and arteriovenous malformations. In addition to above applications others include carotid and peripheral arteriography, thoracic and abdominal aortography, pulmonary arteriography, and ventriculography. Future applications may include intracerebral and coronary arteriography. DSA provide low-risk out patient screening arteriography. In DSA, a computer is used to subtract an initial image without contrast medium taken directly from the image intensifier from the angiographic images with contrast medium in the blood vessels. The intravenous administration of contrast material permits safe outpatient screening for arterial disease. The bone, soft-tissue and gas are removed leaving only the

contrast-medium- filled blood vessels in the final subtracted arterial images. DSA requires cooperative patient who can keep still and hold breath, because any type of movement can cause image degradation. Abdominal examinations are performed after an intravenous injection of 20 mg hyoscine butyl bromide to prevent peristalsis in the gastrointestinal tract and thoracic examinations can be done with ECG-triggered gating to prevent cardiac pulsations. Advantages of DSA are both volume and iodine concentration of the nonionic contrast medium used for each run, because of the high contrast resolution of the imaging system in DSA, reduction in the length of the procedure, reduction in the size of the catheters used from 6-8 Fr down to 3-5 Fr, reduction in the number of radiographic film used, reduction in the radiation dose to the patient and angiographic staff. Disadvantage of DSA is the fact that the images it produces are inferior in the quality of their spatial resolution to those produced by conventional film angiography. The magnitude of this difference in image quality has been reduced with technical improvements in DSA systems. In intravenous DSA, the high contrast resolution of the imaging system allows nonionic contrast medium to be injected intravenously in order to produce arterial images in patients with no femoral pulse, large volume of contrast medium is injected rapidly by a pump injector

Digital Subtraction AngiographyC H A P T E R

11


through a catheter positioned in the SVC or right atrium. The contrast medium is diluted as it passes through the lungs and into the left side of the heart and systemic circulation, but the images are of good quality. Complication of intravenous DSA are hemorrhage from puncture site, vascular thrombosis, peripheral embolization, aneurysm, local sepsis, injury to local structures, guidewire fracture, and vasovagal reaction, and vascular disorders. For peripheral angiography carbon dioxide digital subtraction angiography can be used as an alternative or adjunct to iodinated contrast in

vascular imaging and interventional procedures. Its unique qualities make it useful in diagnostic as well as therapeutic procedures in arteries and veins. Because of its endogenous gaseous attributes, it is nonallergic, does not affect the kidneys, and can be used in unlimited quantities. Compared with iodinated contrast, the low viscosity of CO2 permits greater sensitivity for arterial hemorrhage and arteriovenous fistulas as well as it is more facile using microcatheters. Certain simple principles must be used with CO2 as a contrast agent. When used appropriately, CO2 is safe and can be useful when iodinated contrast is either not sufficient or is contraindicated.

Computed RadiogRaphy

Computed radiography (CR) uses similar equipment as conventional radiography except that in place of a film to create the image, an imaging plate (IP) made of photostimulable phosphor is used. The imaging plate housed in a special cassette is placed under the body part or object to be examined and the X-ray exposure is made. Thereafter, instead of taking an exposed film into a darkroom for developing in chemical tanks or an automatic film processor, the imaging plate is run through a special laser scanner, or CR reader, that reads and digitizes the image. The digital image can then be viewed and enhanced using software that has functions very similar to other con ventional digital image-processing software, such as contrast, brightness, filtration and zoom. The CR imaging plate (IP) contains photo-stimulable storage phosphors, which store the radia tion level received at each point in local electron energies. When the plate is put through the scanner, the scanning laser beam causes the electrons to relax to lower energy levels, emitting light that is detected by a photomultiplier tube (Fig. 12.1), which is then converted to an electronic signal. The electronic signal is then converted to discrete (digital) values and placed into the image processor pixel map. The signals generated by the photodetector as the plate is being scanned are amplified and digitized by an

analog-to-digital converter (ADC). The spatial resolution of computed radiography is influenced by factors such as the phosphor plate thickness, the readout time and the diameter of the laser beam, which is typically about 100 μm. Imaging plates can theoretically be reused thousands of times if they are handled carefully. An image can be erased by simply exposing the plate to a room-level fluorescent light. Most laser scanners automatically erase the image plate after laser scanning is complete. The imaging plate can then be reused. Reusable phosphor plates are environmentally safe. A fundamental limitation of CR is the time required to read the latent image. Since, the decay time of the phosphor luminescence is ~0.7 μs, typically the readout of a 3,000×3,000 pixel image can takeover half a minute to complete. An improvement can be obtained by line scanning, where a full line of pixels is stimulated and read out simultaneously instead of single pixels. This line-scanning approach requires a linear array of laser light sources, e.g. laser diodes, as well as a linear array of photodetectors as wide as the imaging plate, and gives rise to readout times of less than 10 seconds.

advantages over Conventional Radiography

• Nosilver-basedfilmorchemicalsarerequiredto process film.

Computed and Digital RadiographyC H A P T E R

12


Fig. 12.1: Schematic mechanism of CR system: Imaging plate-coated with photostimulable phosphor (PSP) exposed to X-rays and contains image data. In CR reader, imaging plate is read using red laser beam, which is swept across the plate by a rotating polygonal mirror. The light emitted by imaging plate is converted into electrical signal and used to form image

• Reduced film storage costs because imagescan be stored digitally.

• Computed radiography often requires fewerretakes due to under or over exposure which results in lower overall radiation dose to the patient.

• Imageacquisitionismuchfasterimagepreviewscan be available in less than 15 seconds.

• Byadjustingimagebrightnessand/orcontrast,a wide range of thicknesses may be examined in one exposure, unlike conventional film based radio graphy, which may require a different expo sure or multiple film speeds in one exposure to cover wide thickness range in a component.

• Images can be enhanced digitally to aid ininterpretation.

• Images canbe storedondiskor transmittedfor off-site review.

• EvergrowingtechnologymakestheCRmoreaffordable than ever today. With chemicals, dark-room storage and staff to organize them, you could own a CR for the same monthly cost while being environmentally conscious, depending upon the size of the radiographic operation.

digital RadiogRaphy

Digital radiography (DR) is a form of X-ray imaging, where digital X-ray sensors are used instead of tra ditional photographic film (Fig. 12.2). Advantages include time efficiency through bypassing chemical processing and the ability to digitally transfer and enhance images. Also less radiation can be used to produce an image of similar contrast to conventional radio graphy. Digital radiography is essentially filmless X-ray image capture. In place of X-ray film, a digital image capture device is used to record the X-ray image and make it available as a digital file that can be presented for interpretation. The advantages of DR over film include immediate image preview and availability, a wider dynamic range which makes it more forgiving for over and under exposure as well as the ability to apply special image processing techniques that enhance overall display of the image. DR has the potential to reduce costs associated with processing, managing and storing films. The digital image capture devices include flat panel detectors (FPDs). FPDs are classified in two main categories:1. Indirect FPDs: Amorphous silicon (a-Si) is the

most frequent used FPD in the medical imaging industry today. Combining a-Si detectors with a scintillator in the detector’s outer layer, which is made from Cesium Iodide (CsI) or Gadolinium Oxysulfide (Gd2O2S), converts X-ray to light. BecausetheX-rayenergyisconvertedtolight,the a-Si detector is considered an indirect image capture technology. The light is then channeled through the a-Si photodiode layer where it is converted to a digital output signal. The digital signal is then read out by Thin Film Transistors (TFTs) or by fiber coupled Charged Couple Devices (CCDs). The image data file is sent to a computer for display.

2. Direct FPDs: Amorphous Selenium Flat Panel Detectors (a-Se) are known as “direct” detectors because X-ray photons are converted directly to charge. The outer layer of the flat

Computed and Digital Radiography 139

panel in this design is typically a high voltage bias electrode. The bias electrode accelerates the captured energy from an X-ray exposure through the amorphous selenium layer. X-ray photons flowing through the selenium layer create electron hole pairs. These electron holes transit through the selenium based on the potential of the bias voltage charge. As the electron holes are replaced with electrons, the resultant charge pattern in the selenium layer is read out by a TFT array. The image data file is sent to a computer for display.

Computed radiography (CR) and DR use a medium to capture X-ray energy and produce a digitalimage.Bothalsopresentanimagewithin

Fig. 12.2: Schematic diagram showing types of DR flat panel detectors (FPD): (i) Direct conversion flat panel detectors: X-rays are converted to electronic signal by amorphous selenium photoconductor; (ii) Indirect conversion flat panel detector: X-rays are convertedtovisiblelightbyscintillator,whichisfurtherconvertedtoelectronicsignalbysiliconphotodiode.Electronicsignalisconverted to digital image by TFT arrays

seconds of exposure. CR involves the use of a cassette that houses the imaging plate, similar to traditional film-screen systems to record the image whereas DR captures the image directly onto a flat panel detector without the use of a cassette. Image processing or enhancement can be applied on both DR and CR images due to the digital format. DR may offer improved workflow for routine procedures due to the elimination of cassette manipulation and processing, as well as a greater capacity to limit radiation exposure. CR continues to offer flexible position of the image receptor for procedures such as those done for portable film, trauma, surgical cases and cross-table lateral projections.

Picture archiving and communication system (PACS), is based on universal DICOM (Digital imag ing and communications in medicine) format. DICOM solutions are capable of storing and retrieving multi modality images in a proficient and secure manner in assisting and improving hospital workflow and patient diagnosis (Flow chart 13.1). The aim of PACS is to replace conventional radiographs and reports with a completely electronic network. These digital images can be viewed on monitors in the radiology department, emergency rooms, inpatient and outpatient departments, thus saving time, improving efficiency of hospital and avoid incurring the cost of hard copy images in a busy hospital. The three basic means of rendering plain radiographs images to digital are computed radiography (CR) using photostimulable phosphor plate technology; direct digital radiography (DDR) and digitizing conventional analog films. Non image data, such as scanned documents like PDF (portable document format) is also incorporated in DICOM format. Dictation of reports can be integrated into the system. The recording is automatically sent to a transcript writer’s workstation for typing, and can also be made available for access by physicians, avoiding typing delays for urgent results. Radiology has led the way in developing PACS to its present high standards. Picture archiving and communication system (PACS) consists of

four major components: The hospital information system (HIS) with imaging modalities such as radiography, computed radiography, endoscopy, mammography, ultrasound, CT, PET-CT and MRI, a secured network for the transmission of patient infor mation, workstations for interpreting and reviewing images and archives for the storage and retrieval of images and reports. Backup copies of patient images are made provisioned in case the image is lost from the PACS. There are several methods for backup storage of images, but they typically involve automatically sending copies of the images to a separate computer for storage, preferably off-site. In PACS, no patient is irradiated simply because a previous radiograph or CT scan has been lost; the image once acquired onto the PACS is always available when needed. Simultaneous multilocation viewing of the same image is possible on any workstation connected to the PACS. Numerous post-processing soft copy manipulations are possi ble on the viewing monitor. Film packets are no longer an issue as PACS provides a filmless solution for all images. The PACS can be integrated into the local area network and images from remote villages can be sent to the tertiary hospital for reporting. Picture archiving and communication system (PACS) is an expensive investment initially but the costs can be recovered over 5 years period. It requires a dedicated maintenance. It is important

Picture Archiving and Communication SystemC H A P T E R

13

Picture Archiving and Communication System 141

to train the doctors, technicians, nurses and other staff to use PACS effectively. Once PACS is fully operational no films are issued to patients. Picture archiving and communication system (PACS) breaks the physical and time barriers associated with traditional film-based image retrieval, distribution and display. PACS can be linked to the internet, leading to

teleradiology, the advantages of which are that images can be reviewed from home when on call, can provide linkage between two or more hospitals, outsourcing of imaging examinations in understaffed hospitals. The PACS is offered by all the major medical imaging equipment manufacturers, medical IT companies and many independent soft ware companies.

Flow chart 13.1: Picture archiving and communication system (PACS)

IODINATED INTRAVASCULAR AGENTS

Intravascular radiological contrast media are iodine containing chemicals which add to the details in any given CT scan study and thereby aid in the diagnosis. Contrast overall enhances the body tissues. It helps to show the lesion which could not be appreciated on plain scan or shows the lesion better than what was seen in the plain scan. Contrast was first introduced by Moses Swick. Iodine (atomic weight 127) is an ideal choice element for X-ray absorption because the korn (K) shell binding energy of iodine (33.7) is nearest to the mean energy used in diagnostic radiography and thus maximum photoelectric inter actions can be obtained which are a must for best image quality. These compounds after intravascular injection are rapidly distributed by capillary per meability into extravascular-extracellular space and almost 90 percent is excreted via glomerular filtration by kidneys within 12 hours. Following iodinated contrast media are available:1. Ionic monomers, e.g. Diatrizoate, Iothalamate,

Metrizoate.2. Nonionic monomers, e.g. Iohexol, Iopamidol,

Iomeron.3. Ionic dimer, e.g. Ioxaglate.4. Nonionic dimer, e.g. Iodixanol, Iotrolan.

The amount of contrast required is usually 1-2 ml/kg body weight. Normal osmolality of human serum is 290 mOsm/kg. Ionic contrast media have much higher osmolality than normal human serum and are known as high osmolar contrast media (HOCM), while nonionic contrast media have lower osmolality than HOCM and are known as low osmolar contrast media (LOCM). Side effects or adverse reactions to contrast media are divided as:1. Idiosyncratic anaphylactoid reactions.2. Nonidiosyncratic reactions like nephrotoxicity

and cardiotoxicity. Adverse reactions are more with HOCM than LOCM, hence LOCM are preferred. Delayed adverse reactions although very rare are, however, more common with LOCM and include iodide mumps, systemic lupus erythematosus (SLE) and Stevens-Johnson syndrome. Principles of treat-ment of adverse reaction involves mainly five basic steps: ABCDEA: Maintain proper airwayB: Breathing support for adequate breathingC: Maintain adequate circulation. Obtain an IV

accessD: Use of appropriate drugs like antihistaminics

for urticaria, atropine for vasovagal hypotension and bradycardia, beta agonists for bronchospasm, hydrocortisone, etc.

Computed Tomography Contrast MediaC H A P T E R

14

143Computed Tomography Contrast Media 143

E: Always have emergency back-up ready including ICU care.

Following intravascular iodinated agent arterial opacification takes place at approximately 20 seconds with venous peak at approximately 70 seconds. The level then declines and the contrast is finally excreted by the kidneys. These different phases of enhancement are used to image various organs depending on the indication. Spiral CT, being faster is able to acquire images during each phase, thus provide much more information.

ORAL CONTRAST

The bowel is usually opacified in CT examinations of the abdomen and pelvis as the attenuation value of the bowel is similar to the surrounding structures and as a result pathological lesions can be obscured. Materials used are barium or iodine based preparations, which are given to the patient to drink preceding the examination to opacify the gastro intestinal tract.

Barium Sulfate

Barium sulfate preparations are used for evaluating gastrointestinal tract. Barium (atomic weight 137) is an ideal choice element for X-ray absorption because the K shell binding energy

of barium (37) is near to the mean energy used in diagnostic radiography and thus maximum photoelectric interactions can be obtained which are a must for best image quality. Moreover, barium sulfate is nonabsorbable, nontoxic and can be prepared into a stable suspension. For CT scan of abdomen, 1000-1500 ml of 1-5 percent w/vol barium sulfate suspension can be used. Severe adverse reactions are rare. Rarely mediastinal leakage can lead to fibrosing mediastinitis while peritoneal leakage can cause adhesive peritonitis.

Iodinated Agents

Iodine containing oral contrast agents like gastro-graffin and trazograf are given for evaluating gastro intestinal tract on CT scan.

AIR

Air is used as a negative per rectal contrast medium in large bowel during CT abdomen and during CT colonography.

CARBON DIOXIDE

Rarely, carbon dioxide is used for infradiaphragmatic CT angiography in patients who are sensitive to iodinated contrast.

Index

A

Abdominal angiography 81 aorta 81, 95f branches 82 radiograph 34Acromion process 130Advantages over conventional radiography 137Amorphous selenium flat panel detectors 138Analog-to-digital converter 137Anatomical segmental division of lungs 28Angiogram of abdominal aorta 82f celiac arterial trunk 83f posterior cerebral circulation arterial phase 74f, 75f capillary phase 75f, 76f venous phase 77f renal arteries in pyeloureterogram phase 87f right anterior cerebral circulation arterial phase 70f, 71f capillary phase 71f, 72f venous phase 72f, 73f right renal artery early arterial phase 85f late arterial phase 86f nephrogram phase 86f superior mesenteric artery 84fAngiography of lower limb 95f, 97f-101fAngle of Louis 79Ankle joint 60Anterior cerebral artery 69 communicating artery 69 interosseous artery 90f spinal arteries 73

Arch of aorta 80fArtery of foregut 83 midgut 85Ascending thoracic aorta curves 80fAtlantoaxial junction 20fAxillary artery 89f, 93f

BBarium enema 111 study 111f sulfate 143 swallow 103 study 104f, 105fBase of distal phalanges 131 middle phalanges 131 proximal phalanges 131Basilar artery 73Body of clavicle 130 scapula 130Brachial artery 89f, 93fBranches of aortic arch 67 external carotid artery 67Bucky table 121

CCalcaneus 132Capitellum 130Carbon dioxide 143Cavernous portion of internal carotid artery 67Celiac arterial trunk 83 trunk 81Cephalic veins 91Cerebral circulation 67, 68 cortical veins 74

Cervical spine 13Cervicothoracic junction 18fCircle of Willis 68Clivus canal angle 27Coccyx 16Computed radiography 137, 139, 140 contrast media 142Coupled charged couple devices 138Craniovertebral angle 27

D

Dacrocystogram 125, 125f, 126fDeep cerebral veins 74 palmar arch 92f vein 92Digital radiography 138 subtraction angiography 135 veins 91Direct digital radiography 140Distal femur 132 phalanges 131Dorsolumbar spine 14Dural sinuses 76, 79

E

Elbow joint 41, 128f, 130tEpiphysis 132External iliac and common iliac artery 97f, 98fExtracranial carotid arteries 67

F

Fallopian tubes 123, 123f, 124Femoral head 131Fibular shaft 132Forearm 44

Page numbers followed by f refer to figure and t refer to table


G

Greater trochanter 131 tuberosity 130

H

Head of humerus 130 radius 130Hilgenreiner’s line 49Hip joint 49, 129f, 131tHysterosalpingogram 121, 122f-124f

I

Inferior angle of scapula 130 mesenteric artery 84Internal carotid artery 67-69

J

Jugular bulb 78

K

Knee joint 55, 129f, 132

L

Lateral cuneiform 132 decubitus 34 epicondyle 130Leech-Wilkinson cannula 124Lesser trochanter 131 tuberosity 130Locating lesions of lungs 31Location of arches of foot 64fLow osmolar contrast media 142Lower end of radius 131 ulna 131 limb 49

angiography 95 arterial system 96 venous system 102Lumbosacral spine 14, 24f X-ray 25f, 26fLung fissures 31

M

Medial border of scapula 130 cuneiform 132 end of clavicle 130 epicondyle 130Metacarpal heads 131 veins 91Metatarsal shafts 132Micturating cystourethrogram 117, 118f, 119fMiddle cerebral artery 69 cuneiform 132 of coracoid process 130 phalangeal base 132 phalanges 131Multiplanar reconstructed CT scan image of elbow joint 42f forearm 44f hand and wrist joint 46f shoulder joint 37f upper arm 40f reconstructed images of abdomen 35f joint 61f foot with ankle 63f knee joint 56f lower leg with ankle 59f thorax 29f

N

Nasal cavity 9 septum 9

Normal intracranial arterial system 67 venous system 74 venous anatomy of brain 78

O

Olecranon process 130Orbit 10Ossification centers 127

P

Paranasal sinuses 6f, 10Patella 132Pelvic phleboliths 34Perkin’s line 49Petrous portion of internal carotid artery 67Phalangeal shafts 132Pituitary fossa 5fPopliteal artery 97, 100, 100fPosterior cerebral arteries 69, 73 communicating arteries 67, 69 fossa veins 74, 78 inferior cerebellar artery 69Production of X-rays 133Profunda femoris artery 96Proximal femoral shaft 131 phalanges 131 tibia 132

R

Radial arteries 90f, 94Radiological anatomy of female reproductive organs 121 importance of craniovertebral junction 27 vertebral column in spinal injuries 24Renal artery 88 angiogram 87

Index 147

Retrograde urethrogram 120Root of coracoid process 130

S

Sacrum and coccyx X-ray 27fShaft of humerus 130Shoulder joint 37, 127f, 130tSim’s speculum 124Spinal canal 21 cord 21Subclavian artery 89fSuperficial femoral artery 96, 99f palmar arch 91f veins 91Superior internal carotid artery 69 mesenteric arteriogram 85 artery 83Systemic lupus erythematosus 142

T

Teres minor 37Thoracic aorta 79, 80f

Tibial shaft 132 tubercle 132Trochlea 130Turkish saddle 9

U

Ulnar artery 90f, 94 shaft 130Upper arm 38 gastrointestinal tract 104f, 105f limb 37 angiography 88 venous system 94

V

Vein of Galen 74 Trolard and Labbe 74Venous system 91Vertebral arteries 69Vertebrobasilar circulation 69

W

Wrist joint and hand 44

X

X-ray 28 abdomen 36f ankle and foot 63f joint 62f cervical spine 15f-20f open mouth 20 right posterior oblique for intervertebral foramina 19f cervicothoracic junction 18f chest 29f-32f dorsolumbar spine 22f, 23f elbow joint 42f, 43f foot 64f, 65f forearm 45f hand and wrist joint 47f hip joint with pelvis 52f knee joint 57f skyline 58f KUB region 114f leg 60f, 61f pelvis with both hip joints 51f right hip joint 51f, 52f shoulder joint 38f, 39f skull 3f, 4f, 5, 5f, 6, 6f-8f, 11f, 12f thigh 54f, 55f upper arm 40f, 41f

atlas on x-ray and angiographic anatomy, 1e (2013) [unitedvrg]

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