What is the common direction of angling the CR in an AP axial projection (Towne method) of the skull?

In an AP axial projection of the skull using the Towne method, the central ray (CR) is angled 30 degrees caudad. This specific angling is designed to properly visualize the occipital bone and to obtain a clear view of the foramen magnum, which is necessary for evaluating the cranial structures.

The caudad angulation directs the central ray downward and towards the feet, effectively positioning it to capture the skull from an angle that minimizes distortion and maximizes the details of the posterior aspect. The 30-degree angle is specifically chosen based on anatomical landmarks, allowing radiologists to accurately assess the occurrences in the occipital region.

This technique is widely utilized in clinical practice for skull radiography due to its effectiveness in providing critical diagnostic information about skull fractures, lesions, and other abnormalities. The proper angling is essential to ensure that the anatomy is well defined and that important structures are not obscured.