Which projection is likely to produce the greatest distortion?

The 37° AP axial projection of the skull is likely to produce the greatest distortion due to the nature of how the x-ray beam interacts with the object being imaged. In radiography, distortion is influenced by the angle of the x-ray beam in relation to the object being examined, as well as the receptor.

In this case, the 37° angulation significantly alters the geometry of the skull being projected onto the image receptor. When an x-ray beam is angled more steeply, it can result in an exaggerated view of structures, leading to a change in perceived size and shape. This is particularly relevant for the skull, which has complex contours and varying thicknesses. The greater the angulation from being perpendicular to the plane of interest, the more distortion is likely to occur because different parts of the skull will be projected in varying degrees, causing foreshortening or elongation of certain anatomical features.

This is contrasted with the other projections, which have either a standard position (AP and PA) or less steep angulations (20° PA axial), and are therefore likely to produce less distortion, as they maintain a more direct alignment with the object being imaged. The less extreme angles help preserve the geometric relationships of the skull's structure