Bone Density Test (DEXA)

A bone density test determines if you have osteoporosis, a disease that causes bones to become more fragile, and likely to break.

A bone density test uses x-rays to measure the amount of calcium and minerals in a segment of bone.  The bones that are most commonly measured are the hip, spine, and forearm.

A DEXA can

• identify decreases in bone density before you break a bone
• determine your risk of broken bones
• monitor the success of your osteoporosis treatment

Preparation:

Bone density tests are easy, fast, and painless.  Virtually no preparation is needed.

Please tell us if you may be pregnant, or if you have recently had a barium enema,or a CT with contrast, as these agents can interfere with the test.

During the test:

You will lie on a padded  table, while a mechanical arm passes over your body.

The amount of radiation is very low, much less than a chest x-ray.

The test usually takes less than 10 minutes.

Results:

Your results are reported in two numbers, a t score and a z score.  The t score is your bone density compared with the normal bone density of a healthy young adult.  The z score is your bone density compared with the average bone density of  adults your age.

The t score defines whether you have normal bone density, osteopenia, or osteoporosis.

Normal: t score -1 or above

Osteopenia: t score between -1 and -2.5

Osteoporosis: t score -2.5 and below

Your doctor can further explain your results and discuss what measures are recommended to help you prevent fractures.