The Peripheral DEXAs are simpler and only take around 10 minutes. You place your finger, hand, forearm, or foot in a small device that obtains a quick bone density reading.
There is an additional procedure called Lateral Vertebral Assessment (LVA). An LVA is done at many centers. LVA is a low-dose x-ray examination of the spine to screen for vertebral fractures. This test is also performed on the DEXA machine. The LVA test adds only a few minutes to the Central DEXA procedure.
Before your scan, the technician may ask you to complete a quick questionnaire. This helps the doctor determine if you have osteopenia, osteoporosis, or some other medical condition. Your DEXA results reveal your bone mineral density (BMD). Basically, how dense your bones are. The report also lists your T-score and Z-score, which we’ll discuss in more depth in a moment!
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- The green figures indicate above average BMD; the darker the green, the better your BMD.
- The yellow figures indicate that you have normal bone density.
- The orange figures indicate osteopenia (a T-score between -1.0 to -2.5), where bone density is below normal and may lead to osteoporosis.
- The red figures indicate osteoporosis (-2.5 and below), which is severe bone loss.
For both rows pictured above, the number on the top of each figure is the T-score for bone mineral density (BMD). This will be reported for any bone density test you’ve taken (Left Femur, Right Femur, Spine, or Total Body).
At the bottom of each figure is a “%” score associated with the T-score value. Using a scale of 1 to 100, the “%” score is how your BMD compares to people of your gender in the standard group of “Young Adults” that’s used to diagnose osteopenia and osteoporosis. For example, if your T-score was 0.6, your “%” score would be “73%” suggesting that your BMD was better than 73 out of 100 people of your gender in the comparison group and worse than 27 out of 100!
- How do you check bone density? The only truly accurate way to check your bone density is with a DEXA scan. Regular x-rays will not give you the details (T-score and Z-score) your doctor needs to make an accurate diagnosis.
- What is the actual name of the bone density test? DEXA (or DXA) stands for Dual Energy X-Ray Absorptiometry. There are two types: Central and Peripheral. The first covers your entire skeleton; the second focuses on your extremities, such as your hands or feet.
- How much does it cost for a bone density test? In the US, Medicare covers the cost of your DEXA scan every two years. If you need more scans, please check with your insurance provider for complete coverage details. In Canada, the Federal Government says that if you’re 65 and never had a DEXA, Canadian Medicare will cover it. They’ll also let you do follow-up DEXAs if you need them, every 2 years and cover them. Sometimes, if your treatments are annual, Medicare will cover the cost. What if you’re under 65? Most commercial providers will cover your initial DEXA if you’re post-menopausal and you have risk factors (such as smoking, genetics, or being under- or overweight.) If your health insurance does not cover the cost of your DEXA scan, you will have to pay out of pocket.
- How often should I have a bone density test?
Once you reach one of the milestones listed below, you should have a DEXA scan every 2 years:
- You are a woman 65 or older
- You are a postmenopausal woman under 65
- You are a man 70 or older
- You are 50 or older and recently suffered a bone fracture, especially from a minor fall
- I have a metal plate/object in my body (head, arm, leg etc.), is it still safe/effective to have a body composition scan? Yes. Since the metal object will be present in both initial and future scans, the readings will still be helpful since there is no change in the object. The metal will not greatly affect readings. A DEXA scan’s beams can’t interact with the metal object like an MRI machine’s will, so while the surrounding tissue will be classified incorrectly as bone, readings will still be consistent from scan to scan.
Frequently Asked Questions
Sources
Bone Density Test, Osteoporosis Screening & T-score Interpretation. (n.d.). Retrieved from https://www.nof.org/patients/diagnosis-information/bone-density-examtesting/.
What Women Need to Know. (n.d.). Retrieved from https://www.nof.org/preventing-fractures/general-facts/what-women-need-to-know/#menopause.
Demontiero, O., Vidal, C., & Duque, G. (2012). Aging and bone loss: new insights for the clinician. Therapeutic advances in musculoskeletal disease, 4(2), 61–76. doi:10.1177/1759720X11430858
Stewart, T. L., Ralston, S. H. (2000). Role of genetic factors in the pathogenesis of osteoporosis. J Endocrinol. 166(2), 235e245. doi:10.1677/joe.0.1660235
Osteoporosis. (n.d.). Retrieved from https://www.nia.nih.gov/health/osteoporosis.
Kendler, D. L., Kiebzak, G. M., Ambrose C. G., et al. (2006). Effect of calcium tablets on interpretation of lumbar spine DXA scans. Journal of Clinical Densitometry, 9(1), 97–104. doi:10.1016/j.jocd.2005.12.002
Mettler, F. A., Huda, W., Yoshizumi, T. T., Mahesh, M. (2008). Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology 248 (1), 254–263. doi:10.1148/radiol.2481071451
Briot, K. (2013). DXA parameters: beyond bone mineral density. Joint Bone Spine, 80(3), 265–269. doi:10.1016/j.jbspin.2012.09.025