Bone Densitometry

Bone densitometry is a special X-ray that measures your bone density and can be used to help predict your risk of bone fractures. This test is used to determine bone mineral content and density to diagnose osteoporosis. Osteoporosis is the loss of bone that may cause the bone to become weak. Osteoporosis commonly occurs in women entering menopause. However, it may be found in men and in people with other diseases.

PREPARATION FOR TEST

No preparation necessary.

WHO SHOULD BE TESTED?

  • All women older than 65.

  • Postmenopausal women (50 to 65) with risk factors for osteoporosis.

  • People with a previous fracture caused by normal activities.

  • People with a small body frame (less than 127 pounds or a body mass index [BMI] of less than 21).

  • People who have a parent with a hip fracture or history of osteoporosis.

  • People who smoke.

  • People who have rheumatoid arthritis.

  • Anyone who engages in excessive alcohol use (more than 3 drinks most days).

  • Women who experience early menopause.

WHEN SHOULD YOU BE RETESTED?

Current guidelines suggest that you should wait at least 2 years before doing a bone density test again if your first test was normal. Recent studies indicated that women with normal bone density may be able to wait a few years before needing to repeat a bone density test. You should discuss this with your caregiver. 

NORMAL FINDINGS

  • Normal: less than standard deviation below normal (greater than -1).

  • Osteopenia: 1 to 2.5 standard deviations below normal (-1 to -2.5).

  • Osteoporosis: greater than 2.5 standard deviations below normal (less than -2.5).

Test results are reported as a "T score" and a "Z score." The T score is a number that compares your bone density with the bone density of healthy, young women. The Z score is a number that compares your bone density with the scores of women who are the same age, gender, and race.

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.