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Bone DensitometryYour physician has ordered a Bone Densitometry Scan for you to learn more. We have compiled this information about your exam to better inform you and help answer your questions.
The Bone Densitometry staff at all of our facilities is available to answer any additional questions you may have, so please do not hesitate to ask.
The following Information for your Bone Densitometry Scan has been modified from the Radiology Info website.
Overview of Bone Densitometry Scan
Preparing for your Bone Densitometry Scan
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Overview of Bone Densitometry Scan
What is a Bone Densitometry Scan (DEXA)?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).
An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography 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. Portable DEXA devices, including some that use ultrasound waves rather than x-rays, measure the wrist, fingers or heel and are sometimes used for screening purposes.Common usesDEXA 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.
The Lateral Vertebral Assessment (LVA), a low-dose x-ray examination of the spine to screen for vertebral fractures that is performed on the DEXA machine, may be recommended for older patients, especially if:
- they have lost more than an inch of height
- have unexplained back pain
- if a DEXA scan gives borderline readings
SafetySpecial care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.
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.Preparing for your Bone Densitometry Scan
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.
When to arrive
Arrive 15 minutes before your scheduled appointment time to check in and fill out any necessary forms.
Other information
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?Scanning
Bone Densitometry Scans are a quick and painless procedure, and usually done 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. The technologist will walk behind a wall or into the next room to activate the x-ray machine.
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 ResultsAll Bone Densitometry Scans are read by a Mass General radiologist or endocrinologist specialty trained in Bone Densitometry imaging and dedicated to the specific area of interest for your study.
Rapid results are essential not only for your peace of mind, but also for your physician to begin planning your treatment immediately, if necessary. After the scan has been read, the results are sent to your physician, who will discuss them with you.
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Locations where Bone Densitometry is performed
How to Schedule a Bone Densitometry ScanA referral from a physician is required for a Bone Densitometry Scan. Physicians may schedule patients using our online scheduling and report access program - ROE.
Additional Information and Resources
MGH Radiology Rounds E-Newsletter
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Massachusetts General Hospital
Division of Musculoskeletal Imaging & Intervention
Yawkey Center for Outpatient Care
55 Fruit Street, 6th Floor
Boston, MA 02114
Phone: 617-724-XRAY (9729)
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