What is the gold standard test to diagnose osteoporosis?

• A. Ultrasound of the bone.
• B. MRI of the hip.
• C. Dual-energy X-ray absorptiometry (DXA).
• D. CT scan of the spine.

Answer: (C)

The test that most accurately confirms osteoporosis is dual-energy X-ray absorptiometry, which directly measures bone mineral density at key fracture sites such as the hip and spine. It provides precise, reproducible results and uses well-established diagnostic thresholds (for example, a T-score of -2.5 or lower indicates osteoporosis). The method exposes only a small amount of radiation and allows classification of bone density with clear cutoffs linked to fracture risk. Other imaging modalities can give other information or assess anatomy, but they do not provide the standardized density measurement needed to diagnose osteoporosis reliably, so they are not the gold standard.