What is the cassette size for a lateral wrist X-ray?

For a lateral wrist X-ray, the correct cassette size typically used is indeed a full 10" x 12" in a vertical orientation. This size ensures that the entire wrist is adequately captured within the frame, providing the necessary detail and clarity for diagnostic purposes.

When performing a lateral wrist X-ray, using a full-sized cassette allows for optimal visualization of the wrist anatomy, including the carpal bones, distal radius, and ulna. This is crucial for identifying any potential fractures or abnormalities.

The other options suggested smaller sections of the cassette, which would not adequately cover the anatomy of interest in a lateral view. Using anything less than the full 10" x 12" size might lead to inadequate imaging, resulting in loss of information essential for diagnosis. Therefore, choosing the full cassette size maximizes the chances of capturing all necessary details for a proper examination.