Dual energy X-ray absorptiometry, or DEXA, is a bone density test that uses special, extremely low dose X-rays to diagnose or determine risk for osteoporosis.
DEXA scans measure bone mineral content at the hip or spine. It is the best way to screen for osteoporosis and assess risk for fractures.
DEXA scans are not the same as bone scans. Bone scans are a nuclear medicine study requiring an injection beforehand and are usually used to detect fractures, cancer, infections and other abnormalities in the bone.