A DEXA scan is a bone density scan. DEXA stands for dual energy X-ray absorptiometry. It is used to see if there are any signs of osteopenia, osteoporosis or other bone problems. An X-ray technician performs the procedure. A DEXA scan is also useful for determining the severity of an already diagnosed bone problem or for seeing if treatment for a bone problem is working.
People who are at risk of osteoporosis undergo routine DEXA scans. If a doctor suspects that a patient may have osteoporosis, he or she may order a DEXA scan. People who have osteoporosis may be scanned regularly to see if the disease has worsened. People who are currently being treated for osteoporosis may also be scanned to determine if their treatment is working or if the disease is progressing.
Patients will not be asked to do anything to prepare for the exam. Doctors may talk to them about the exam to prepare them mentally and help them understand the process and the results. Doctors may also ask their patients to avoid certain things in the weeks leading up to a DEXA scan and on the day of the test. Those things may include,
•No prior radionuclide studies for two weeks
•No barium contrast studies for two weeks
•No metal in clothing
The scan only takes about 15 minutes. The patient will be asked to lie down on a table. An X-ray scans the hips and the spine. The doctor will print out photos of the X-rays and will look at them to determine if there are any signs of osteoporosis or other bone diseases, or if a diagnosed disease has improved or worsened. Doctors do this by comparing the amount of calcium that appears in the X-rays of the patient’s bones with the amount of calcium found in the bones of a healthy person.
DEXA scans are non-invasive, so there is no recovery time. Doctors will normally inform the patient about what to do next and how to deal with their diagnosis. Patients who have a hard time lying down for long periods may feel stiff after the procedure, but that should wear off quickly once the patient moves around.
Doctors will receive results from the scan within a few days; some may even get them the same day. The results are reported as a T-score. A T score of -1 to -2.5 is considered osteopenia, and T-score of less than -2.5 is considered osteoporosis. Doctors use this scale to determine the severity of the bone disease and to come up with the right treatment. Most doctors will recommend that their patients begin treatment as soon as possible to stop the disease from progressing even more. They may continue to order regular DEXA scans to check on the patient’s progress and to decide if there are any other issues that may need treatment.