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

In a Posteroanterior (PA) projection of the hand, it is essential for the anterior, or palmar surface, to be in contact with the image receptor (IR). This orientation allows for an accurate representation of the hand's bones and joints by providing a direct view of the structures from the posterior aspect toward the front. When the anterior surface is placed against the IR, it ensures that the X-ray beam passes through the back of the hand to the front, producing a clear image of the phalanges, metacarpals, and carpals in their proper alignment.

Placing the posterior surface against the IR would result in an inverted view of the hand, which could obscure important anatomical details and lead to misinterpretation of the images. Likewise, positioning the hand with either the lateral or medial surfaces in contact with the IR would not provide the necessary visualization of the hand structures as intended in a PA view. Thus, using the palmar surface ensures that the X-ray captures the anatomy accurately and effectively.