BONE DENSITY
A bone mineral density (BMD) test can help your health care provider confirm a diagnosis of Osteoporosis. The test can help in several ways:
- BMD testing is one of the most accurate ways to assess your bone health.
- When repeated over time, it can be used to monitor your rate of bone loss.
- It can detect osteoporosis at its earliest stage, so treatment can begin sooner.
- If you are being treated for osteoporosis, BMD testing can help your health care provider monitor your response to the treatment.
Several different kinds of machines can do BMD testing. The most common methods use low-dose x-rays (about one-tenth the radiation dose of a chest x-ray). While you are lying in on a cushioned table, a scanner passes over your body. Typically, the machine takes x-rays of your lower spine and hip. In most cases you won't need to undress. There are portable machines that just measure the bone density in your wrist or heel and these may be useful for screening purposes.
The results of your Bone Density test are usually reported as a "T score" and "Z score."
- The T score compares your bone density with that of healthy young women.
- The Z score compares your bone density with that of other people of your age, gender, and race.
In either score, a negative number means you have thinner bones than the standard. The more negative the number, the thinner your bones. A T score is within the normal range if it is a positive number, or at least no more negative than -1.0. (For example, -0.5 is within the normal range, although it is getting borderline.) Your doctor will help you interpret the results.
(Source: NIH, National Library of Medicine Encyclopedia 2007)
