Which surface of the foot should be in contact with the IR during a recumbent lateral projection?

In a recumbent lateral projection of the foot, the surface that should be in contact with the image receptor (IR) is the lateral surface of the foot. When positioning the foot for this view, it is essential for the lateral aspect to be in contact with the IR to accurately demonstrate the anatomy of the foot, including the tarsal bones, metatarsals, and phalanges, as well as to visualize any potential fractures or pathologies.

Positioning the foot in this manner allows radiologists to gain a comprehensive view of the lateral profile of the foot, which is crucial for diagnostic purposes. The other surfaces—medial, superior, and dorsal—would not provide the correct lateral view needed for a recumbent lateral projection, as they would either obscure necessary anatomical details or fail to demonstrate the foot's structure from the required plane.