In a right AP axial oblique projection of the cervical spine (RPO), how many degrees should the patient rotate?

• A. 30 degrees
• B. 45 degrees
• C. 60 degrees
• D. 90 degrees

Answer: (B)

To visualize the cervical foramina on an AP axial oblique view, you rotate the patient so the foramina are in profile to the imaging plane. The standard rotation is 45 degrees. This angle places the zygapophyseal joints and the foramina in the correct orientation, giving the clearest view with minimal superimposition from other structures. Rotating less than 45 degrees tends to blur or obscure the foramina, while rotating more than 45 degrees can distort the anatomy or place the wrong foramina in view. A 90-degree turn would essentially give a lateral view, not the oblique view needed. So, 45 degrees is the established rotation to best demonstrate the cervical foramina in an AP axial oblique projection.