What is the correct cassette size for an AP elbow in horizontal orientation?

The correct cassette size for an AP elbow in a horizontal orientation is indeed half of the 10" x 12" size. When positioning for an AP elbow view, particularly in a horizontal beam projection, using a cassette that is sufficiently large to accommodate the region of interest while allowing for proper alignment is crucial.

In this case, a half-size cassette effectively covers the area needed for an elbow examination while maintaining ease of handling and positioning. The dimensions of 8" x 10" correspond closely to half of the 10" x 12" size, making it practical for a focused exposure while ensuring adequate coverage of the elbow joint. This size supports optimal image quality by minimizing any potential distortion or misrepresentation of the anatomy involved.

This choice aligns well with common radiographic practices aimed at ensuring both patient safety and image quality. Proper utilization of the cassette size facilitates achieving the correct positioning and alignment of the elbow for an accurate diagnostic image.