Bone Densitometry scanning, also called dual-energy x-ray absorptiometry (DXA or DEXA) or Bone Density Scan, is an enhanced form of x-ray technology that is used to measure bone loss. DEXA is today's established standard for measuring bone mineral densitometry (BMD).
A DEXA scan is a painless medical procedure that helps physicians diagnose and treat medical conditions. It involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging. DEXA is most often performed on the lower spine and hips.
How to Schedule a Bone Densitometry Scan
A prescription from a physician is required for a DEXA exam. You may need a referral from your physician or pre-authorization from your insurance company. Consult with your physician before scheduling your appointment. Call your preferred location to schedule an appointment.
DEXA Services are performed in the following locations; please contact us for more information or to schedule an appointment:
St. Joseph's Regional Medical Center, Paterson: 973.754.4343
St. Joseph's Wayne Hospital, Wayne: 973.956.3312
St. Joseph's Ambulatory Imaging Center, Clifton: 973.569.6300
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.
DEXA is also effective in tracking the effects of treatment for osteoporosis and other conditions that cause bone loss. The DEXA test can also assess an individual's risk for developing fractures.
Bone Densitometry 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 a parathyroid condition, such as hyperparathyroidism.
- have experienced a fracture after only mild trauma.
- have had x-ray evidence of vertebral fracture or other signs of osteoporosis.
Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation.
State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures those parts of a patient's body not being imaged receive minimal radiation exposure.
What should I expect BEFORE my Bone Densitometry Scan?
Food and drink
On the day of your Bone Densitometry Scan you may eat normally. You should not take calcium supplements for at least 24 hours before your exam.
What to wear
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, eyeglasses and any metal objects or clothing that might interfere with the x-ray images.
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.
Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy because radiation can be harmful to the fetus. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby.
What will I experience DURING my Bone Densitometry Scan?
Bone Densitometry Scans are a quick and painless procedure, and are usually conducted on an outpatient basis.
In the DEXA examination, which measures Bone Density in the hip and spine, the patient lies on a padded table. An x-ray generator is located below the patient and an imaging device, or detector, is positioned above.
To assess the spine, the patient's legs are supported on a padded box to flatten the pelvis and lower (lumbar) spine. To assess the hip, the patient's foot is placed in a brace that rotates the hip inward. In both cases, the detector is slowly passed over the area, generating images on a computer monitor.
The patient must hold very still and may be asked to keep from breathing for a few seconds while the x-ray picture is taken to reduce the possibility of a blurred image.
Length of scan
The DEXA Bone Densitometry Scan is usually completed within 10 to 30 minutes, depending on the equipment used and the parts of the body being examined.
What should I expect AFTER my Bone Densitometry Scan?
You may resume normal activity after your Bone Densitometry Scan.
Bone Densitometry Scan Results
All DEXA exams are read by our specially trained radiologist. After the scan has been read, the results are sent to your physician, who will discuss them with you.
Additional Information and Resources
For further information on Bone Densitometry/DEXA scans - click here