Which of the following is NOT a common evaluation site during a DXA scan?

• A. The hip
• B. The lumbar spine
• C. The forearm
• D. The skull

Answer: (D)

The evaluation of bone density using a DXA (Dual-energy X-ray Absorptiometry) scan frequently focuses on specific anatomical sites that are most indicative of overall bone health and are commonly associated with osteoporosis assessment. The hip and lumbar spine are standard sites because they are weight-bearing areas where fractures are prevalent in osteoporotic patients. The forearm can also be assessed, as it can provide useful information, particularly in patients with risk factors for osteoporosis.

In contrast, the skull is not a common evaluation site during a DXA scan. This is primarily due to the limited relevance of skull bone density in assessing osteoporosis and fracture risk, as fractures in that area are less common compared to the hip, spine, and forearm. Furthermore, the structural makeup and function of the skull differ significantly from these other sites, making it a less effective area for evaluating bone density related to systemic osteoporosis. Therefore, identifying the skull as not a common evaluation site aligns with standard practices in bone densitometry.