Which test measures bone density for osteoporosis screening?

Which test measures bone density for osteoporosis screening?

• A. X-ray
• B. Ultrasound
• C. DEXA scan
• D. MRI

Answer: (C)

Bone density measurement is the key test for osteoporosis screening, and the test that does this most directly is the DEXA scan. DEXA, or dual-energy X-ray absorptiometry, uses two low-dose X-ray beams to quantify bone mineral density at critical sites like the spine and hip, which are most predictive of fracture risk. This measurement yields a T-score that helps define osteoporosis (typically a T-score of -2.5 or lower) and guides treatment decisions. X-rays mainly show existing fractures and structural changes rather than early density loss. Ultrasound can assess some peripheral sites but is not the standard for diagnosing osteoporosis in the central skeleton, and MRI does not measure bone density for screening.

Bone density measurement is the key test for osteoporosis screening, and the test that does this most directly is the DEXA scan. DEXA, or dual-energy X-ray absorptiometry, uses two low-dose X-ray beams to quantify bone mineral density at critical sites like the spine and hip, which are most predictive of fracture risk. This measurement yields a T-score that helps define osteoporosis (typically a T-score of -2.5 or lower) and guides treatment decisions. X-rays mainly show existing fractures and structural changes rather than early density loss. Ultrasound can assess some peripheral sites but is not the standard for diagnosing osteoporosis in the central skeleton, and MRI does not measure bone density for screening.