In a lateral elbow positioning, what should be noted about the relationship between the ulna and humerus?

In a lateral elbow positioning, it is essential for the ulna to be flat on the cassette. This positioning ensures that both the ulna and humerus are in a true lateral view, which is critical for accurate imaging of the elbow joint. When the ulna is flat against the cassette, it allows for the best possible visualization of the joint space and surrounding anatomy, as any elevation or tilt could result in distortion of the image, making it difficult to assess for fractures or other pathologies.

This correct positioning also aids in properly aligning the x-ray beam with the joint space, ensuring that the radiographic projection captures all necessary details for diagnosis. Maintaining the ulna flat against the cassette is crucial during the lateral projection of the elbow to achieve the desired clarity and detail in the resulting images.