Final answer:
The three major sites for BMD scans are the hip, lumbar spine, and forearm with DEXA being a common method that measures bone density and body composition by using dual X-ray beams.
Step-by-step explanation:
The three major sites that are commonly used for Bone Mineral Density (BMD) scans include:
- The hip (specifically the femoral neck or the total hip region).
- The lumbar spine.
- The forearm (particularly the distal radius).
BMD scans, particularly Dual-energy X-ray Absorptiometry (DEXA), are critical tools used to measure bone density and assess the risk of osteoporosis. The DEXA scan works by directing two low-dose X-ray beams through the body and measures the amount of energy absorbed by bone and other tissues. The results, using standard mathematical formulas, can determine not only the bone density but also the fat content in the body.
While DEXA scans are predominantly known for measuring bone density, they also have the capability to analyze body composition in terms of bone mass, lean tissue mass, and fat mass. This dual function makes DEXA scans highly valuable in both osteoporosis diagnosis and overall health assessment.