skull imaging final

Positions and Techniqueof Skull imaging

By Dr. Tamer Ahmed KamalProfessor of Radio diagnosis

Benha University

SKULL Bones connected bysutures to protect brain

CALVARIUM= SKULL CAP Consists Of bones linked by sutures

BONES OF CALVARIUM

FRONTAL

PARIETAL

OCCIPITAL

TEMPORAL

SPHENOID

SUTURES

LAMBDOIDALSUTURE

SAGITTALSUTURE

CORONALSUTURE

LANDMARKS

LAMBDA - MIDPOINT OFLAMBDOIDALSUTURE

BREGMA - MIDPOINT OF CORONALSUTURE

SURFACE ANATOMY AND REFERENCE POINTS

Anterior Skull

PARA NASAL SINUSES

Cranium

Ventral Skull

Sphenoid bone

Occipital Bone

Lateral Skull

Internal Skull

Indications for Skull x ray

• Head Injury with suspected penetrating injury.• Head injury when CT is not available.• Head injury with CSF or Blood loss via the

nose.• Head injury with major trauma.

Basic skull projections

The Routine views of the cranium are :

• PA skull (Caldwell)• Lateral skull • AP axial (Towne`s)

SKULL PA

Patient PositionErect or Supine

Part Position Mid Sagittal plane perpendicular to midline of grid.

OML is perpendicular to the cassette.

Respiration Suspended respiration.Central Ray •PA :- perpendicular to cassette exiting nasion.

•Caldwell - Direct 15 degrees Cauded exiting nasion •Center Cassette to central ray.

NB If patient is obese a small radiolucent sponge may be needed under forehead.

PA skull

SKULL AP

Patient PositionPatient supine

Part Position Mid saggital plane perpendicular to cassette

Place arms by side or across the chest

Respiration Suspended respiration

Central Ray •AP :- perpendicular to cassette exiting nasion

•Axial :- Direct 15 degrees Cephalad

•Center Cassette to central ray

SKULL LATRAL

Patient PositionSeated erect or semi prone

Part Position Mid saggital plane parallel to cassette

IOML is perpendicular to front edge of the cassette

Inter-pupillary line is perpendicular to cassette


•Direct Perpendicular Entering Two Inches Superior To EAM

•Center Cassette to central ray

Central Ray

SKULL Lateral

Dorsal Decubitus

Patient Position Supine

Part Position

•Support head on sponge with site of interest closest to cassette

•Mid saggital - plane parallel

Inter-pupillary line is perpendicular to cassette


Central Ray

Direct horizontal and perpendicular entering two inches superior to EAM

Center Cassette to central ray

SKULL Lateral

Patient positionErect or supine

Part position

•Center mid saggital plane to mid line of grid device and adjust to be perpendicular

•Have patient flex Neck

•Place IOML perpendicular

•Place top of cassette at level of cranial vertex


Central ray

Direct through foramen Magnum with caudal angle 30 degree to 37 degree to IOML

Central ray enters approx 2.5 inches superior to glabella and passes through EAM

SKULL AP AXIAL- Towne method

Patient PositionErect or prone

Part Position •Patient rest head over fore head and nose

•Place arms in comfortable position

•Adjust shoulders to lie in same transverse plane

•Adjust head to the mid sagittal plane

•OML is perpendicular to the cassette


Central Ray 25 degrees cephalad - entering 3.8 cm inferior to

external occipital protuberance

and exiting 3.8 cm superior to nasion

SKULL PA AXIAL- Hass method

Seated Erect at Head unit or supine on elevated table support

•Patient extend head and rest on vertex •Center and adjust mid saggital plane perpendiculaar to cassette

•Adjust IOML parallel to plane of cassette if possible •immobilize head

Suspended respiration

•Direct through sella Turcica - perpendicular to IOML •Entering between angles of the mandible •Central ray passes through a point 1.9 cm anterior to level of EAM

Sub mento vertical- Schuller Method

Patient Position

Part Position

Respiration

Central Ray

Patient Position Seated erect or semi prone

Part Position

•Center a point 1.8 cm superior and 1.8 cm anterior to EAM to cassette adjust mid sagittal plane parallel to cassette •inter pupillary line is perpendicular to cassette•IOML is perpendicular to front edge of cassette

Respiration Obtain radio graph through suspended respiration

Direct perpendicular entering 1.9 cm superior and 1.9 anterior to EAM to center of cassette Collimate the sphenoid bone

Sella Turcica - Lateral

Central Ray

Patient PositionErect or semi prone

Part Position Center affected orbit to cassette

Have patient rest head on zygoma - nose and chin Adjust AML perpendicular to cassette

Rotate midsaggital plane 53 degrees from cassette

Respiration suspended respiration

Central Ray

•Direct perpendicular entering 2.5 cm superior and 2.5 cm posterior to elevated top of ear attachment •exiting orbit closest to cassette •Ensure colliminnation is extremely close •Center cassette to central ray

Optic canalREHSE Method

Patient PositionErect or supine on elevated table

Part Position

Hyper-extended neck and have patient rest head on vetex

Center and adjust midsaggital plane perpendicular to cassette

Adjust IOML parallel with cassette


Central Ray

•Direct perpendicular to IOML entering midway between zygomatic arches

•Central ray enters approximately 1 inch posterior to outer canthi

Zygomatic arches

Patient PositionErect or semi prome

•Position head in lateral ;position with affected side closest to cassette

•from true latral position , rotate midsaggital plane 15 degree toward cassette

•IOML is parallel to transverse axis of cassette

•interpupillary line is perpendicular to cassette


Central Ray

•Direct 15 degree caudal enetring approx 5 cm posterior and 5 cm superior to EAM •Farthest from Cassette

•Central ray exit 2.5 cm to EAM of affected side •Center cassette to center ray

Petro mastoid Bone

Axio-latral Oblique

Part Position

Common positioning Errors

Tilt occurs when the interpupilary line is not at 90 to the film.

Rotation occurs when the median Saggital plane is not parallel to the film

Thank You

skull imaging final

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