What is the primary purpose of imaging the lumbar spine using DXA?

• A. To visualize muscle attachment sites
• B. To assess the vertebral alignment
• C. To measure bone mineral density
• D. To evaluate spinal mobility

Answer: (C)

The primary purpose of imaging the lumbar spine using dual-energy X-ray absorptiometry (DXA) is to measure bone mineral density (BMD). This imaging technique is specifically designed to assess the amount of mineral content within the bones, providing crucial information about bone strength and the risk of osteoporosis or fractures.

Measuring BMD in the lumbar spine is particularly important because it is one of the most common sites for osteoporotic fractures. By determining the density of the vertebrae, healthcare providers can evaluate a patient’s bone health and make informed decisions regarding treatment or preventative measures. DXA is highly regarded for its precision and low radiation exposure.

Other purposes, such as evaluating spinal mobility or assessing vertebral alignment, do not align with the primary function of DXA. While these factors can be important in the overall assessment of spinal health, they are not the main intention of a DXA scan. Similarly, visualizing muscle attachment sites falls outside the scope of what DXA imaging is designed to accomplish, as it focuses on bone density rather than muscle or soft tissue analysis.