Osteoporosis and Bone Density Tests
What Types of Bone Density Tests Are Available?
There are several different machines used to measure bone density. "Central" machines measure bone density in the hip, spine, and total body. "Peripheral" machines measure bone density in the finger, wrist, kneecap, shinbone, and heel. Here are some of the different types of bone density tests:
- DXA (Dual Energy X-ray Absorptiometry) measures the spine, hip, or total body.
- pDXA (Peripheral Dual Energy X-ray Absorptiometry) measures the wrist or heel.
- SXA (single Energy X-ray Absorptiometry) measures the wrist or heel.
- QUS (Quantitative Ultrasound) uses sound waves to measure density usually at the heel.
- QCT (Quantitative Computed Tomography) is most commonly used to measure the spine, but can be used at other sites.
- pQCT (Peripheral Quantitative Computed Tomography) measures the wrist.
- RA (Radiographic Absorptiometry) uses an X-ray of the hand.
With the information obtained from a bone density test, you and your health care provider can decide the necessary prevention or treatment steps that are best for you.
For in-depth information, see WebMD's Beyond DXA: Other Bone Mineral Density Tests.
Are Bone Density Tests Used to Monitor Osteoporosis Treatment?
The American Medical Association and some other reputable medical organizations have determined that repeat bone density testing (DXA scans) is not necessary to monitor osteoporosis treatment in the first three years of treatment or in prevention on a routine basis. Bone density changes so slowly with treatment that the changes may be smaller than the measurement error of the machine. They feel that repeat DXA scans cannot distinguish between a real increase in bone density due to treatment or a mere variation in measurement from the machine itself.
Several other organizations like the National Osteoporosis Foundation, however, still support repeat testing at 1 or 2 year intervals during treatment. Ask your health care provider what is right for you.