Clinical indication:
Pathology of base of skull and sphenoid sinuses
Region:
Base of skull, sutures sphenoid sinus
Patient’s Position:
The patient is sitting AP position.
The infra-orbitalmeatal line should be parallel to the IR by vertex of the skull is centered to the IR by raising the patient’s head & chin.
The mid sagittal plane is perpendicular to the IR.
Cassette:
Size: 10’’x12’’ Orientation: Landscape
FFD/SID:
100cm
Central ray:
Central ray is towards the point midway between external auditory meatus and the point midway between angles of mandible.
The central ray is perpendicular to IR.
Grid:
Yes
Respiration:
Not related
Exposure factors:
70-80kVp 16-20mAs
Collimation:
Collimate laterally to include soft tissues and lateral border of skull, superiorly include mandible and inferiorly include occiput of the skull