SKULL AXIAL PROJECTION
Towne • AP with caudal angulation • Posterior Fossa and Occipital Evaluation
Exposure Factors
Equipment: With bucky. Position: Supine.
Plate Size and Orientation
Patient Position
SUPINE POSITION
Patient lying on table in supine position (face up)
Use radiolucent support if necessary to maintain position
Visible Anatomical Structures
Occipital Bone
Complete occipital squama
Sella Turcica
Dorsum sellae
Clinoid Processes
Posterior
Occipital Foramen
Posterior border
- Petrous bones - Petrous portions of temporals
- Internal auditory canals
- Foramen magnum - When well centered
- Jugular processes - Occipital jugular processes
- Venous sinuses - Transverse and sigmoid
- Mastoids - Mastoid air cells
Patient Positioning
Central Ray Angulation Options
Angulation depends on reference line used:
Note: Angulation adjusts according to reference line used for positioning
Central Ray Trajectory
Entry Point
Between eyebrows, upward
Exit Point
Foramen magnum - skull base
Ray direction: CAUDAL
From above (glabella) downward (occipital)
Central ray centers the cassette during its trajectory
Patient Instructions
"Hold your breath during exposure"
Maintain complete immobility - Do not move head during exposure
Clinical Indications
Technical Considerations
Correct Angulation
Verify if using OML (30°) or IOML (37°) to avoid error.
Image Quality
Centered foramen magnum, symmetric petrous bones, complete occipital.
Safety
Protect eyes in caudal angulation. Use lead apron.