Dual Energy X-ray Absorptiometry (DEXA)

Dual energy X-ray absorptiometry (DEXA) is a painless, low-radiation scan that measures bone mineral density to diagnose osteoporosis and assess fracture risk. It compares bone density to young-adult (T-score) and age-matched norms, guiding treatment decisions and monitoring response. DEXA is typically recommended for older adults or those with risk factors such as fractures, long-term steroid use, or low body weight.

A DEXA scan measures bone mineral density to diagnose osteoporosis and osteopenia and estimate fracture risk. It’s also used to monitor bone loss over time and assess body composition (lean and fat mass) for clinical or fitness evaluation. The test is quick, noninvasive, low-radiation, and commonly used for older adults, postmenopausal women, or people on medications that affect bone health.

Dual-energy X-ray absorptiometry (DEXA) uses two low-dose X-ray beams at different energies to measure how much radiation is absorbed by bone and soft tissue. Detectors record attenuation; software separates bone from lean and fat tissue to calculate bone mineral content and density. The quick, noninvasive, low-radiation scan is commonly used to diagnose osteoporosis and estimate fracture risk in the spine and hip.

DEXA is generally better than dual-photon absorptiometry. It offers higher accuracy and precision for bone mineral density, faster scans, lower radiation exposure, and improved spatial resolution. DEXA is the current clinical standard for diagnosing osteoporosis and assessing body composition; dual-photon techniques are older and largely replaced by DEXA in modern practice.

A DEXA bone scan is safe for most people. It is a quick, noninvasive X‑ray test that uses very low radiation—much less than a chest X‑ray—so risks are minimal. It measures bone density and fracture risk. Pregnant women should avoid it. Tell staff about recent contrast scans or metal implants. Overall, benefits for diagnosis and treatment planning outweigh the small radiation risk.

Dual energy X-ray absorptiometry (DXA) offers precise, gold-standard measurement of bone mineral density for diagnosing osteoporosis and predicting fracture risk. It’s quick, noninvasive and uses a very low radiation dose. DXA provides high reproducibility for monitoring treatment, can scan spine, hip or whole body, and accurately assesses body composition (lean vs. fat mass) for clinical and research use.