CAMRT Radiography Practice Exam

To best demonstrate the axillary portion of the lower, posterior left ribs after a routine PA and lateral chest x-ray, how should you position the patient?

1. Supine position, full expiration

2. RPO erect, full inspiration

3. RPO erect, full expiration

4. LAO position, shallow breathing

The correct answer is: RPO erect, full expiration

To effectively demonstrate the axillary portion of the lower, posterior left ribs, positioning the patient in an RPO (Right Posterior Oblique) erect position with full expiration is optimal. This positioning allows the left ribs to be more prominently visualized. In the RPO position, the left side of the patient's body is rotated away from the imaging plate, which can help to project the left axillary ribs clearly onto the film. The erect position is ideal for this examination as it helps to reduce the effects of any superimposing structures and enhances the overall quality of the radiograph by allowing gravity to assist in the positioning of abdominal contents, thereby reducing potential obstructions over the ribs. Full expiration is essential because it provides a more uniform exposure and allows the diaphragm to move upwards, reducing the amount of air in the thoracic cavity. This helps to better delineate the ribs and obtain a clearer image of the structures of interest, minimizing the risk of motion blur that could occur with shallow or irregular breathing. While other options may suggest various positions or breathing techniques, the RPO erect position with full expiration is specifically designed to maximize the visual clarity of the axillary portion of the ribs in question.