DEXA scan
Pronunciation: DEK-sah scan
Also written as: DEXA — dual-energy X-ray absorptiometry
Dual-energy X-ray absorptiometry test measuring bone mineral density and body composition in pediatric patients.
Full Definition
A specialized imaging technique that uses two different X-ray energies to measure bone mineral density, lean body mass, and fat mass with high precision and low radiation exposure. In pediatric endocrinology, DEXA scans are used to assess bone health in conditions such as growth hormone deficiency, hypogonadism, chronic illness, and steroid-induced osteoporosis. The scan provides Z-scores comparing the patient to age-, sex-, and ethnicity-matched peers, as T-scores are inappropriate in growing children. Interpretation requires consideration of pubertal status, as bone mineral density normally increases during adolescence. The test is also valuable for monitoring response to treatments affecting bone metabolism.
Usage
Usage note: Use Z-scores rather than T-scores when reporting pediatric results.
In Context
- "DEXA scan revealed low bone mineral density with a lumbar spine Z-score of -2.1." — Bone health assessment
- "Serial DEXA scans will monitor bone density response to growth hormone treatment." — Treatment monitoring plan