Osteoporosis Screening – DEXA

DEXA, or DXA, stands for “Dual Energy X-ray Absorptiometry.” By measuring bone mineral density, it helps physicians diagnose osteoporosis and calculate an individual’s risk of bone fractures. Some of these tests are called p-DEXA, which scans periphery bones such as fingers, toes, heel, and wrist. Other tests are called Central DEXA and are scans of central body areas such as the hips and spine. Both use low dose radiation—about as much as you receive going through airport security systems.

Women older than age 65 should have annual DEXA scans. That helps physicians measure the rate of bone density loss. With that information they can plot the best course of action for you. “At-risk” women older than age 60 also should have an annual scan. The at-risk group includes problems such as chronic renal and liver disease, chronic respiratory disease, rheumatoid arthritis, and celiac disease. Heavy smokers also are considered at risk.

Your scan results are expressed in positive and minus numbers. Scores of minus-2.5 or more, for example, mean osteoporosis. Scores between minus-1 and minus-2.5 mean some bone loss and a higher risk of fractures. Good, healthy scores are +1 and above.

There are two other columns of numbers. The “T score” compares your bone density to women in their thirties, when their bones are strongest. The “Z score” compares your bone density to other women your age. Those numbers help determine the rate of bone density loss.

DEXA scans are widely used because they are fast, relatively inexpensive, and covered by almost all insurance policies. After the first one you should schedule a scan every one or two years to provide your doctor with an extremely accurate chart of developing problems or your treatment progress.

You will be asked to fill out a questionnaire that will  be used to assess your risk of fractures. From there, the procedure is similar to a traditional X-ray. The DEXA scan should take between 10 and 30 minutes. The only discomfort will come from remaining in the same position during the scan—make sure to tell the technician if you have had any hip or back injuries. Your scan will be read by a radiologist who will, in turn, send the results to your doctor. The doctor will decide a course of action that could include exercise, diet and/or prescription medicine.

Make sure you have the required doctor’s prescription or referral and that the facility you want to use accepts your insurance plan. The facility may have preparation instructions for you to follow. Do not take calcium supplements for 48 hours prior to the scan. Wear comfortable, loose-fitting clothing that does not have metal buttons or zippers. Beyond that, prepare the way you would for any other X-ray. Don’t wear jewelry, watches, eye glasses, or anything else that contains metal.