bone mineral density scan (... MIH-neh-rul DEN-sih-tee skan)
An imaging test that measures bone density (the amount of bone mineral contained in a certain volume of bone) by passing x-rays with two different energy levels through the bone. It is used to diagnose osteoporosis (decrease in bone mass and density). Also called BMD scan, DEXA, DEXA scan, dual energy x-ray absorptiometric scan, dual x-ray absorptiometry, and DXA.