At which sites are Single X-ray Absorptiometry (SXA) typically utilized?

• A. Spine and pelvis
• B. Forearm and heel
• C. Hip and wrist
• D. Skull and spine

Answer: (B)

Single X-ray Absorptiometry (SXA) is primarily utilized at sites with lower bone mineral density and where peripheral measurements are advantageous for assessing the risk of osteoporosis. The forearm and heel are commonly chosen sites because they are areas that can effectively indicate skeletal health without requiring the more complex setup of central DXA scans.

The forearm is especially useful for assessing cortical bone density, which is helpful in an osteoporotic population where fragility fractures are common. The heel, or calcaneus, can be measured conveniently and rapidly using SXA, and it is a good predictor of overall bone health since it reflects both trabecular and cortical bone.

These locations provide useful data regarding bone density that may correlate with fracture risk and help in screening for osteoporosis, making them the best choices for SXA applications. Thus, the utilization of forearm and heel is integral in the context of bone densitometry, especially for preliminary assessments or screenings.