Bone Densitometry or (DEXA) dual-energy-x-ray-absorptiometry is an enhanced form of x-ray technology that is used to measure bone loss. DEXA is used to diagnose osteoporosis, a condition that more often affects women after menopause but may also be found in men. Osteoporosis involves a gradual loss of calcium, causing the bones to become thinner, more fragile and more likely to break. A DEXA test can be used to assess a patient’s risk for developing fractures, and determine if preventive treatment is needed.
Bone Densitometry is recommended for the following reasons.
- Post-menopausal woman and not taking estrogen.
- Have a personal or maternal history of hip fracture or smoking.
- Are a post-menopausal woman who is tall (over 5 feet 7 inches) or thin (less than 125 pounds).
- Are a man with clinical conditions associated with bone loss.
- Use medications that are known to cause bone loss, including corticosteroids such as Prednisone, various anti-seizure medications such as Dilantin and certain barbiturates, or high-dose thyroid replacement drugs.
- Have type 1 (formerly called juvenile or insulin-dependent) diabetes, liver disease, kidney disease or a family history of osteoporosis.
- Have high bone turnover, which shows up in the form of excessive collagen in urine samples.
- Have a thyroid condition, such as hyperthyroidism.
- Have experienced a fracture after only mild trauma.
- Have had x-ray evidence of vertebral fracture or other signs of osteoporosis.
Preparation
Inform your physician if you recently had a barium examination or have been injected with a contrast material for a computed tomography (CT) scan or radioisotope scan. You may have to wait 10 to 14 days before undergoing a DEXA test.
On the day of the exam you may eat normally. You should not take calcium supplements for at least 24 hours before your exam. You should wear loose, comfortable clothing, avoiding garments that have zippers, belts or buttons made of metal. You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.
Exam
The DEXA examination takes about thirty minutes and is a simple, painless and noninvasive procedure. A radiologic technologist will conduct the exam and be with you at all times. You will be asked to lie on your back on a padded table. As you are relaxing comfortably, a movable arm passes above your hip and spine. You will not feel anything during the exam. The exam emits a very small amount of radiation, with two different energy levels to assess the differences of the bone density.
Results
The LRG board certified radiologist will study the images and provide a written report which includes a description of the findings. Reports are available to your physicians within 24 hours of the completion of the exam. The report could take longer if we are waiting for studies from an outside facility for comparison. If the results are urgent your physician may acquire a preliminary report by phone.