Bone density scanning, also called dual-energy x-ray absorptiometry (DEXA) or bone densitometry, is an enhanced form of x-ray technology that is used to measure bone loss. DXA is today's established standard for measuring bone mineral density (BMD).
An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Imaging with x-rays involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the body’s internal environment. X-rays are the oldest and most frequently used form of medical imaging.
DEXA is most often performed on the lower spine and hips. In children and some adults, the whole body is sometimes scanned. Peripheral devices that use x-ray or ultrasound are sometimes used to screen for low bone mass. In some communities a CT scan with special software can also be used to diagnose or monitor low bone mass (QCT). This is accurate but less commonly used than DEXA scanning.