Bone Density Test (DXA Scan)
Osteoporosis, a condition seen most commonly with aging, is associated with an increased risk of breaking bones (fractures). Early detection of osteoporosis is possible through the use of bone density testing. A type of x-ray called DXA (pronounced ‘dexa’) uses a very low-energy x-ray beam to evaluate the calcium content of bones. The hip, spine and forearm are sites that may be measured.
The ability of a DXA scan to predict the likelihood of having a fracture is very strong, better than checking a cholesterol level to predict the likelihood of heart disease. A DXA scan helps your doctor decide if treatment is needed to keep your bones strong.
Who should get a bone density test?
The National Osteoporosis Foundation and the International Society of Clinical Densitometry indicate that people with certain risk factors may have a higher risk for breaking bones. These include the following:
- Women age 65 and older
- Older adults with unexplained loss of height (two inches or more)
- Postmenopausal women younger than age 65 with risk factors such as early menopause, long history of smoking, significant alcohol use, family history of osteoporosis, or being underweight for height
- Men age 70 and older, younger men with low testosterone levels, or those receiving lupron shots
- Adults with an unexplained fracture of the spine
- Adults with a fracture that occurred with very little injury
- Adults with a disease or condition associated with low bone mass or bone loss, including overactive thyroid or parathyroid, celiac sprue (inability to absorb products that have gluten, the protein in wheat-like foods), anorexia and other conditions
- Adults taking medications associated with low bone mass or bone loss, including prednisone (deltasone, cortisone), certain seizure medication, lupron shots and others
- Anyone considering osteoporosis therapy, to more accurately check risk
- Anyone being treated for osteoporosis to monitor treatment effect
- Anyone not receiving osteoporosis treatment, but in whom low bone density would lead to treatment or other changes in lifestyle to lower risk of osteoporosis.
If you have any of these risk factors, you may want to ask your doctor if a bone density test would be right for you.
Note: A DXA scan should not be done if you are pregnant. A scan cannot be done if you have undergone an x-ray study involving oral or IV contrast or a nuclear medicine bone scan within a week before the DXA scan. You should not take calcium-containing pills or multivitamins the day before and the day of the scan because it may interfere with the accuracy of bone density measurements.