IMAGING MODALITIES
Bone Density Scanning (DEXA)
About
Bone density tests are simple, safe, and painless. The method of testing bone density is called DEXA (Dual Energy X-ray Absorptiometry). DEXA scans are extremely precise and are one of the most accurate methods available for measuring bone density. Using ultra-low dose X-ray, the DEXA machine scans and measures bone mineral density at various parts of the body, usually the lumbar spine and hips. This highly sensitive test enables us to identify bone loss early and determine whether you are at risk for fracture, by comparing your bone density to your own age group and to a younger age group. It can also monitor your response to treatments for osteoporosis by checking your bone density regularly.
What To Expect
Your DEXA scan will take approximately fifteen minutes. You will be asked to remove items such as your wallet, keys, watch, jewelry, other metal objects. These items will be secured while you are being scanned. You will lie flat on your back on the DEXA scan table and instructed to hold still during the scan.
Patient Preparation
There is very little preparation required.
• If pregnant the exam will not be performed.
• Wear sweat pants (or elastic waist pants or shorts), and a T-shirt. Shoes will be removed for exam.
• Do not wear jewelry, belt buckles, zippers, snaps, or buttons.
• It is okay to eat anytime before or after the exam.
• Be prepared to lie flat on back without moving during the exam (approximately fifteen minutes.)
Common Uses for the Test
DEXA bone densitometry is most often used to diagnose osteoporosis, a condition that 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. The DEXA test can also assess your risk for developing fractures. If your bone density is found to be low, you and your physician can work together on a treatment plan to help prevent fractures before they occur.
DEXA is also effective in tracking the effects of treatment for osteoporosis or for other conditions that cause bone loss.
Bone density testing is strongly recommended if you:
Are a 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.
Risks and Benefits
Benefits:
DEXA bone density testing is the most accurate method available for the diagnosis of osteoporosis. It is also considered an accurate estimator of fracture risk. It will not tell whether you will or will not have a fracture, but gives relative risk of suffering a fracture, just as cholesterol and blood pressure help determine risk for heart disease. A low reading should not cause you to be anxious but may help you set healthy goals. As with other diseases and conditions, early detection is the key to prevention of further bone loss and eventual fractures. DEXA equipment is widely available making DEXA bone densitometry testing convenient for patients and doctors alike.
Risks:
No complications are expected with the DEXA procedure.
