American Registry of Radiologic Technologists (ARRT) Practice Exam

Which position of the elbow will separate the radial head, neck, and tuberosity from the ulna's superimposition?

1. Medial oblique

2. Lateral or external oblique

3. Internal oblique

4. Supine

The correct answer is: Lateral or external oblique

The lateral or external oblique position of the elbow is specifically designed to create separation between the radial head, neck, and tuberosity from the ulna. This position achieves optimal visualization of the elbow joint structures by rotating the arm laterally. As a result, the radial structures are positioned away from the ulna, allowing for a clearer view of the individual components of the radius without superimposition. This technique is particularly important in radiographic imaging to assess any potential injuries or abnormalities of the elbow that may not be clearly visible in other positions. In contrast, the medial oblique and internal oblique positions primarily cause overlapping of the radial and ulnar structures rather than separation. The supine position, while useful for other imaging purposes, does not facilitate the desired separation of the radial and ulnar components as effectively as the lateral or external oblique does. In radiologic examinations, the careful choice of positioning is crucial for accurate diagnosis, making the lateral or external oblique the superior option for this specific imaging requirement.