What is the cassette size used for a PA wrist projection?

The correct cassette size used for a PA wrist projection is 8" x 10". This size is ideal because it allows for sufficient coverage of the wrist joint while providing the necessary detail for diagnostic purposes. Using a smaller cassette, such as one that is 5" x 7", would not adequately capture the entire wrist area, potentially missing important structures that need evaluation. The 10" x 10" size would also be too large, which may lead to unnecessary exposure and increased radiation dose. Therefore, the standard 8" x 10" size strikes the right balance between image quality and radiation safety for this specific projection.