DEXA

Dual Energy X-ray Absorptiometry

Dual X-ray absorptiometry (DXA) is the preferred technique for measuring bone mineral density (BMD). DXA has also been called dual energy X-ray absorptiometry, or DEXA. DXA is relatively easy to perform and the amount of radiation exposure is low. A DXA scanner is a machine that produces 2 X-ray beams, each with different energy levels.

The dual energies are used to cancel out the soft tissue leaving the bony image.


http://www.webmd.com/osteoporosis/guide/dexa-scan