Question

How is the CR directed for a PA axial projection (Caldwell method) of the skull?

a) Perpendicular to the IR
b) 15 degrees caudad
c) 15 degrees cephalad
d) Parallel to the OML

Answer 1

In the Caldwell method for PA axial projection of the skull, the central ray is directed 15 degrees caudad (toward the feet) relative to the image receptor.

Step-by-step explanation:

This is regarding the positioning for a PA axial projection (Caldwell method) of the skull in the field of radiographic imaging. When performing a PA axial projection using the Caldwell method, the central ray (CR) should be directed 15 degrees caudad (toward the feet) to the image receptor (IR). This angle is measured from a perpendicular line to the IR. The positioning is specific to ensure proper visualization of certain anatomical structures of the skull, particularly the frontal sinuses.