Which surface of the hand should be in contact with the IR when performing a routine lateral projection?

For a routine lateral projection of the hand, the correct position involves placing the medial surface of the hand in contact with the image receptor (IR). This positioning is crucial for obtaining an accurate representation of the anatomical structures of the hand, allowing for proper visualization of the bones and joints.

When the medial surface is in contact with the IR, it ensures that the fifth metacarpal and the associated phalanges are clearly outlined and that the alignment of the hand is correct. It helps to minimize overlapping of the structures, which could obscure important diagnostic information. This orientation also allows for a clearer view of the interphalangeal joints and the base of the metacarpals.

In contrast, if the anterior or posterior surfaces were in contact with the IR, the projection would not achieve the proper lateral view, resulting in distortion or improper superimposition of structures. Aligning the limb properly is key to obtaining diagnostic-quality images, which is why the medial surface positioning is emphasized in standard practice for the lateral projection of the hand.