What part of the spine is typically visible on a DXA image?

• A. The anterior elements
• B. The lumbar region
• C. The posterior elements
• D. The sacral area

Answer: (C)

In a dual-energy X-ray absorptiometry (DXA) scan of the spine, the lumbar region is the primary area assessed for bone density. This region specifically includes the lumbar vertebrae, which are the five vertebrae located in the lower back. DXA imaging aims to evaluate bone mineral density (BMD) and is primarily concerned with the trabecular bone found in this area, which is highly responsive to changes in bone health.

The lumbar region contains a significant amount of trabecular bone, which is more affected by osteoporosis and other metabolic bone diseases. Therefore, the typical visibility of the lumbar region on a DXA image allows for accurate assessment and diagnosis of conditions such as osteoporosis.

While the anterior and posterior elements of the vertebrae can be visualized to some extent, they are not the primary focus of the assessment. The sacral area is also present in certain spinal assessments, but it is not the main region examined in a routine DXA scan for evaluating bone density. Thus, the lumbar region is the best answer because it is the standard location evaluated in DXA imaging for bone health.