A bone density test, commonly called a DEXA or DXA scan, is done by using low- dose X-rays to measure the amount of minerals such as calcium in the bones, usually at the lower spine and hips. During the test, the patient lies still on a padded table while an X-ray generator sends thin, invisible beams through the bones. A detector on the other side of the table measures how much X-ray passes through, and this is processed by a computer to calculate bone density. The procedure is quick, non-invasive, and painless, often taking between 10 to 30 minutes. Patients may need to hold their breath briefly to avoid blurred images, and they should avoid calcium supplements at least 24 hours before the test. The test helps diagnose osteoporosis and assess fracture risk.
