Dual Energy X-Ray Absorptiometry (DXA or DEXA)

Every day, physicians use radiography, or x-rays, to view and evaluate bone fractures and other injuries of the musculoskeletal system. However, a plain x-ray test is not the best way to assess bone density.

To detect osteoporosis accurately, doctors use an enhanced form of x-ray technology called Dual-Energy X-ray Absorptiometry (DXA or DEXA). DEXA bone densitometry is today’s established standard for measuring bone mineral density (BMD). DEXA is a quick, painless procedure for measuring bone loss.

Measurement of the lower spine and hips are most often done. More portable devices that measure the wrist, fingers or heel are sometimes used for screening, including some that use ultrasound waves rather than x-rays.

Uses of the Procedure


DEXA bone densitometry is used most often to diagnose osteoporosis. Osteoporosis involves a gradual loss of calcium, causing the bones to become thinner, more fragile, and more likely to break. The DEXA test can also assess your risk for developing fractures. If your bone density is found to be low, you and your physician can work together on a treatment plan to help prevent fractures before they occur. DEXA is also effective in tracking the effects of treatment for osteoporosis or for other conditions that cause bone loss.

Interpreting the Results


T SCORE – This number shows the amount of bone you have compared to a young adult of the same gender with peak bone mass. A score above -1 is considered normal. A score between -1 and -2.5 is classified as osteopenia, the first stage of bone loss. A score below -2.5 is defined as osteoporosis. It is used to estimate your risk of developing a fracture.


Z SCORE – This number reflects the amount of bone you have compared to other people in your age group and of the same size and gender. If it is unusually high or low, it may indicate a need for further medical tests.

This Information was obtained from the Radiology Info Website: www.radiologyinfo.com.