What Does a Dexa Scan Rule Out?

A DEXA scan (also called a DXA scan or dual-energy X-ray absorptiometry) is an advanced X-ray-imaging technique to measure bone density. The scan does not rule out conditions but rather gives the patient a score of bone density.

Uses

• DEXA scans are used to measure bone density so that bone loss can be evaluated when diagnosing osteoporosis or osteopenia. The amount of bone density can predict risk of fractures.

Procedure

• Having a DEXA scan is similar to having a normal X-ray. The patient will be put into position by a radiologist and asked to remain still while the X-ray machine scans the body and takes images.

Results

• Results are read by a radiologist who will forward them to an attending physician for interpretation and recommendation of treatment. Results consist of "T" and "Z" scores.

T Score

• The T score compares the bone density of the patient to the peak mass for the patient's gender. Scores above -1 are normal, while scores within -1 to -2.5 classify the patient with low bone mass (osteopenia). Osteoporosis is diagnosed with scores below -2.5.

Z Score

• The Z score compares the bone density of the patient to the peers of the patient. Medical tests may be ordered for patients with unusually high or low scores.