Bone Density Testing

Osteoperosis is diagnosed through the use of a bone density test. This test serves to estimate the density of a patient's bones and their chances of breaking a bone.

Osteoporosis is a complex disease and not all causes are known. It affects both men and women with one in two women developing osteoporosis in her lifetime. In addition, every three minutes someone has a fracture due to osteoporosis. However, when certain risk factors are present, your likelihood of developing osteoporosis is increased. It is important for you to determine your risk of developing osteoporosis and take action to prevent it now.

Osteoporosis Risk Factors

  • Do you have a small, thin frame and/or are you Caucasian or Asian?
  • Have you or a member of your immediate family broken a bone as an adult?
  • Are you a postmenopausal woman?
  • Have you had an early or surgically induced menopause?
  • Have you been taking high doses of thyroid medication, high or prolonged doses of cortisone like drugs for asthma, arthritis or other diseases?
  • Is your diet low in dairy products or other sources of calcium?
  • Are you physically inactive?
  • Do you smoke cigarettes or drink alcohol?

The more times you answer yes, the greater your risk for developing osteoporosis. If you are concerned about your risk ask your physician if you should have a bone density test. This test safely and accurately measures your bone density and reliably predicts your risk of future fracture.

Bone Density Testing at the Margaret W. Niedland Breast Center

We are dedicated to providing the highest quality screening and diagnostic imaging services. At the Margaret W. Niedland Breast Center we utilize the Hologic® Horizon DXA System, with this system we can provide two powerful screenings tests that could help patients live longer, healthier, more active lives – vertebral fracture assessment and bone density measurement.

What to Expect

Bone density tests are easy, fast and painless. They are usually done on bones that are most likely to break because of osteoporosis, including:

  • Lower spine bones (lumbar vertebrae)
  • The narrow neck of your thighbone (femur), next to your hip joint
  • Bones in your forearm

During the test you lie on a padded platform while a mechanical arm passes over your body. The amount of radiation you're exposed to is very low, much less than the amount emitted during a chest X-ray. The test usually takes about 10 to 30 minutes.

Virtually no preparation is needed for the test. You should avoid taking calcium supplements for at least 24 hours before. Wear loose, comfortable clothing and avoid wearing clothes with zippers, belts or buttons. Remove all metal objects from your pockets, such as keys, money clips or change.


Your bone density test results are reported in two numbers: T-score and Z-score.


Your T-score is your bone density compared with what is normally expected in a healthy young adult of your sex. Your T-score is the number of units — called standard deviations — that your bone density is above or below the average.


What your score means

-1 and above

Your bone density is considered normal.

Between -1 and -2.5

Your score is a sign of osteopenia, a condition in which bone density is below normal and may lead to osteoporosis.

-2.5 and below

Your bone density indicates you likely have osteoporosis.


Your Z-score is the number of standard deviations above or below what's normally expected for someone of your age, sex, weight, and ethnic or racial origin. If your Z-score is significantly higher or lower than the average, it may suggest that something other than aging is causing abnormal bone loss. If your doctor can identify the underlying problem, that condition can often be treated and the bone loss slowed or stopped.