In an AP foot X-ray, where is the central ray directed?

In an anteroposterior (AP) view of the foot X-ray, the central ray is directed at the base of the second metatarsal. This positioning is critical as it provides optimal visualization of the foot's anatomy, allowing for accurate assessment of structures. The base of the second metatarsal serves as a reference point for centering because it is centrally located within the foot and helps to maintain an even distribution of the image details across the various bones of the foot.

If the central ray were directed at other locations, such as the midfoot or the bases of the first or third metatarsals, the resulting image could lead to distortion or inadequate visualization of other important aspects of foot anatomy, potentially affecting diagnostic accuracy. Hence, centering at the base of the second metatarsal is the standard practice for achieving a clear and interpretable X-ray image of the foot.