What is the central ray angle used in an anterior-posterior (AP) axial projection of the cervical spine?

In the anterior-posterior (AP) axial projection of the cervical spine, the correct central ray angle is 15 degrees cephalic. This specific angle is essential to visualize the cervical vertebrae clearly, particularly to open up the intervertebral joint spaces and reduce the superimposition of structures in the cervical region.

When performing an AP axial projection, angling the central ray cephalically helps to align the ray along the natural curvature of the cervical spine, allowing better visualization of the C3 to C7 vertebrae. It effectively projects the cervical vertebrae onto the image receptor without undue distortion, facilitating accurate assessment of pathologies or anatomical positioning.

In contrast, other angles provided do not align with the established protocols for this specific view. An incorrect angle might result in suboptimal imaging that could obscure clinical details necessary for diagnosis. Thus, a 15-degree cephalic angle is the standardized approach, ensuring the best results for imaging the cervical spine in this position.