For a lateral foot radiograph, the central ray should be centered at the base of the:

In a lateral foot radiograph, the central ray is indeed directed at the base of the third metatarsal. This positioning is crucial as it ensures that the entire structure of the foot is captured in a way that allows for accurate assessment of the bones and any potential pathologies. By centering the ray at the third metatarsal, which is centrally located within the foot, the image provides a balanced representation of the lateral aspects of the foot, including the alignment of the metatarsals, phalanges, and joint spaces.

The third metatarsal serves as a key reference point due to its anatomical location and its role in weight-bearing. Positioning the central ray here aids in minimizing distortion and superimposition of the surrounding bones, which can lead to errors in interpretation. Inadequate positioning may result in incomplete views of other structures, such as the navicular and cuboid bones. Hence, targeting the base of the third metatarsal is essential for a diagnostic-quality image that supports effective clinical evaluation.