DEXA scans are used to measure the density of bones in both men and women. It uses X-rays to show how dense bones are in the body. There are two kinds of machines used when testing patients. The larger machines called central DEXA devices that measures bones located in the center of the body, or hips and the spine. Other machines called peripheral DEXA devices are smaller portable machines used to measure bone density in the wrist, heels, and fingers.
How It Works
The machine works by sending low energy X-rays through the bones. They come from two sources so that the doctor can view denser bones more accurately. The rays are measured by a device called a detector. This information is calculated by a computer that figures out the density of the bones. A low score means that the bone density is weak and some mass has been lost. Bones that lose density are more likely to break or facture. Rays used in the test are high and low.
What Happens During the Test?
Your doctor wants you to take a DEXA scan to find out about your bone density. With your over active imagination you visualize damage from the radiation and extreme pressure on your bones. The scan takes about 10 to 20 minutes. It is safe and there is no pain involved. You lie on a table while the doctor passes the machine or scanner over your body.
Before the test you can eat normally but should not take any calcium supplement that day or 24 hour before the exam. Don’t wear clothing with metal zippers and remove keys and jewelry before the scan. You will be asked to remove your clothing and wear a gown. The doctors will ask you to take off jewelry and glasses.
When the spine is tested the legs are supported by a box on the table that flattens the pelvis and lowers the spine. To check the hips the doctor often put the patients foot in a metal brace that rotate the hip inward. The best way to take the test is to lie as still as possible.
When it is completed you can go home. The scanner produces two x-rays one low and the other high. It is scored using a T score that compare your bones to a healthy 30 year old woman. T scores of 1.0 or higher are normal, scores of 1.5 to 2.5 are considered low, and 2.5 or higher means the person has osteoporosis. A Z score is used to compare your score to a person in your age group and gender.
Who Needs the Test?
This test is often preformed on women after menopause. Those with a history of bone loss in the family should get the test. Others that should take the test are women after menopause, men and women with arthritis, and those take certain medications. A person with a history of fractures, diabetes, thyroid condition, and back pain might be a good candidate for this test.
Lifestyle factors that add to thinning bones are drinking too much, smoking, lack of exercise, and diets low in calcium, phosphorus, and Vitamin D. After the test your physician may prescribe medication or recommend that you take a calcium and Vitamin D supplement. They may suggest more exercise and changes in the diet