CAMRT Radiography Practice Exam

Which vertebral structures are best demonstrated with an AP Oblique projection of the lumbar vertebral column with the patient positioned in a 45 degree RPO?

1. Zygapophyseal joints of the left side

2. Zygapophyseal joints of the right side

3. Intervertebral discs

4. Spinous processes

The correct answer is: Zygapophyseal joints of the right side

In the context of an AP Oblique projection of the lumbar vertebral column, positioning the patient in a right posterior oblique (RPO) position effectively demonstrates the zygapophyseal joints on the side opposite to the position of the patient. Therefore, when a patient is positioned in an RPO orientation, the right zygapophyseal joints will be visualized more clearly. This is due to the anatomical orientation of the lumbar vertebrae and their articulations. The oblique projection allows for a better view of the true joint spaces by angling the x-ray beam and positioning the patient in such a way that the zygapophyseal joints are not superimposed by the other vertebrae or structures. In this case, the right zygapophyseal joints are the focus because they are opened up and aligned in this particular oblique projection. In contrast, the other options relate to structures that are not emphasized or demonstrated clearly in this specific projection. The left zygapophyseal joints, intervertebral discs, and spinous processes will not be adequately visualized or may be obscured in this orientation. The left joints would be foreshortened and less discernible, while the intervertebral discs