Bone density scanning, also known as dual-energy, x-ray absorptiometry (DXA) or bone densitometry, is an enhanced form of x-ray technology used to measure bone mineral density (BMD) and loss of bone mass. DXA is most often performed on the lower spine and hips. However, the entire body is sometimes scanned. Body scans are painless, non-invasive procedures with great accuracy in detecting the presence and degree of lost bone mass.