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