What does a DEXA scan measure?

A DEXA scan, also known as dual-energy X-ray absorptiometry, is specifically designed to measure bone mineral density (BMD). This imaging technique uses low-level X-rays to assess the amount of mineral content within the bones, providing essential information about bone health and the risk of fractures.

By evaluating bone density, a DEXA scan helps in the diagnosis of conditions such as osteoporosis, allows for monitoring of bone density changes over time, and is crucial in assessing the effectiveness of treatment therapies for bone-related disorders. This measurement is particularly important for populations at risk of bone density loss, such as postmenopausal women or older adults.

The other options refer to different types of assessments not associated with DEXA. For example, assessing blood flow in the heart typically involves imaging studies like PET scans or MRIs, whereas muscle mass distribution would be evaluated through techniques like bioelectrical impedance analysis or MRI. Tissue hydration levels are typically measured using ultrasound or specialized sensors. Each of these options pertains to different medical assessments, highlighting the unique purpose of a DEXA scan focusing solely on bone mineral density.