If you are a patient with symptoms of osteoporosis (thinning of bone tissue), your doctor has likely mentioned the term "Dexa scan." The word "Dexa" stands for Dual Energy X-Ray Absorptiometry. A physician will determine if you should have a Dexa scan based on several factors. If you have symptoms of osteoporosis (thinning of bone tissue), a Dexa scan will likely be ordered. Symptoms of osteoporosis include the development of painful fractures. These fractures can occur in different areas of the body, including the spine and back. Patients at a high risk of developing osteoporosis will also likely get a Dexa scan. This includes a family history of the condition, low body weight, advanced age and use of certain medications. By age 65, every woman should be screened for osteoporosis.
What is the exam like?
Dexa Scan tests are similar to X-ray tests. They do not generate the same exposure as regular x-rays and are considered safer. You will lie down on a soft surface while a mechanical device swings over parts of your body to provide bone-density images. Multiple x-rays will be taken of your body to measure the amount of calcium and bone minerals in the makeup of your bones. The test will focus on areas of the body that are at risk for fractures, including the spine and hips.
If you are pregnant, you should not have a Dexa scan performed. It is also not recommended for individuals who have had an x-ray with contrast within the last seven days. The previous x-ray may interfere with the results of the scan.
How to prepare for the exam
Your physician will tell you to refrain from taking any calcium supplements at least 48 hours before your scheduled Dexa Scan test. These calcium supplements can skew the Dexa Scan test results. You can continue to eat your normal diet as this will not affect the test results.
Remove jewelry. Dexa Scan tests are still similar to x-rays, and you should avoid wearing any type of metal while having the procedure done. This includes earrings and any other jewelry, regardless of where it is on your body. You may want to wear clothing that is not clingy and is comfortable on the day of your test. Choose clothing that also does not contain any zippers, metal buttons or belts.
You will be given both a T and Z score when you have a Dexa scan. The T score indicates whether your bone density falls within a normal range for a person in her 30s, when bone density peaks, while the Z score is a comparison against other individuals of your age, sex and weight.
If your T score is above 1, your Dexa scan is considered normal. If you score below this number, the scan indicates you have either osteoporosis or osteopenia, the precursor to the condition. The Z score is given in the same format and can help your physician indicate whether you are suffering from a secondary form of osteoporosis.
This test is usually covered by most types of medical insurance and Medicare.