CAMRT Radiography Practice Exam

What is demonstrated on a posterior oblique L-spine?

1. Zygapophyseal joints of the side in contact

2. Inferior articulating process

3. Transverse process

4. Pars interarticularis

The correct answer is: Zygapophyseal joints of the side in contact

The posterior oblique position of the lumbar spine is specifically designed to visualize the zygapophyseal joints, also known as the facet joints, on the side that is in contact with the imaging plate (receptor). In this position, the patient's rotation brings the zygapophyseal joints of the side closest to the film into profile, allowing for optimal visualization and assessment of these crucial articulations in the lumbar region. By using this positioning technique, radiologists can effectively evaluate the alignment, integrity, and any degenerative changes present in these joints, which play a significant role in spinal stability and movement. The other options do have their relevance to the anatomy of the lumbar spine but are not as directly visualized in the posterior oblique projection. The inferior articulating process and pars interarticularis may not be ideally seen, while the transverse process is positioned posteriorly and along the sides, thus not providing the same clear view as the zygapophyseal joints.