When performing a lateral decubitus x-ray, the patient should lie on which side?

In a lateral decubitus x-ray, the patient should lie on the affected side to accurately assess abnormalities or conditions present in that area. This positioning allows gravity to help separate the structures of interest, enhancing the visibility of any pathological changes, fluid levels, or other findings that may be present in the affected lung or organ.

When the patient is on their affected side, the x-ray can effectively demonstrate conditions like pleural effusion, where fluid tends to accumulate and can be seen more clearly in this position. In contrast, lying on the normal side would obscure the view of the affected area and potentially misrepresent the presence or extent of any disease. Other options, indicating a specific side without context regarding the patient's condition, do not consider the necessity for adequate visualization of abnormalities, which is critical for accurate diagnosis and treatment planning.