Which of the following body positions will demonstrate the left zygapophyseal joints of the lumbar spine?

To demonstrate the left zygapophyseal joints of the lumbar spine effectively, the appropriate body position involves specific angling and orientation of the patient that allows for optimal visualization of these joints.

When the patient is positioned at a 45-degree left posterior oblique (LPO), the left zygapophyseal joints are perpendicular to the X-ray beam. This angle opens up the joint spaces, allowing them to be clearly seen on the radiograph. The LPO position specifically places the left side of the lumbar spine closer to the film, providing the best view of the left zygapophyseal joints.

Other options may involve incorrect positioning or angles that do not favorably visualize the left zygapophyseal joints. For example, a right posterior oblique (RPO) would image the right zygapophyseal joints, while a 30-degree left anterior oblique (LAO) or a 15-degree anteroposterior (AP) position would not provide the appropriate angle needed to visualize the left joints clearly. Hence, the 45-degree LPO is the optimal choice for capturing the left zygapophyseal joints during lumbar spine imaging.