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Bone Density Scanning

Bone density scans are available at:

Bone density, or DEXA, scans detect bone loss (osteoporosis) in its earliest stages. Osteoporosis involves a gradual loss of calcium, causing the bones to lose their density. When this happens, breaks can occur from a fall or even from something as simple as a cough or sneeze. However, osteoporosis is preventable, treatable and reversible. 

How It Works 
Bone density scanning, also called Dual-Energy X-ray Absorptiometry (DEXA) or bone densitometry, is performed with an instrument that uses low-energy X-rays to measure bone loss. 

During this noninvasive exam, a part of the body is exposed to a small dose of ionizing radiation to produce pictures of the bones. Scans are typically taken of the lower spine and the hip. Sometimes the whole body or the extremities are scanned. 

How the Procedure Is Used 
A bone density scan is used to judge an individual’s risk for developing osteoporosis, diagnosing osteoporosis, or tracking the treatment of osteoporosis and other conditions that cause bone loss. Osteoporosis most often affects women after menopause, but can occasionally be found in men. 

A bone density test is encouraged if you are: 

  • A post-menopausal woman and are not taking estrogen
  • Thin-framed or small-framed
  • Light-skinned
  • A smoker
  • Someone who drinks alcohol in excess
  • Taking medications known to cause bone loss such as thyroid medication, anti-seizure medications or steroid-based drugs
  • An older patient and have lost more than an inch in height or have unexplained back pain
  • Someone with type 1 (formerly called “juvenile”) diabetes, liver disease, kidney disease or a family history of osteoporosis
  • Someone who has experienced a fracture after only a mild trauma

How to Prepare  On the day of your exam, eat normally. Wear comfortable clothing, as you will lie on a table. You might be asked to change into a gown for the study, or to remove metal items, such as keys or a belt, in the area to be scanned. 

Do not take calcium supplements for at least 24 hours before your exam. 

Inform your physician if you recently had a barium examination or have been injected with a contrast material for a computed tomography (CT) scan. If so, you might 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 might be pregnant. Even though the radiation dosage is very low, many imaging tests are not performed during pregnancy to avoid exposing the baby to radiation. 

The Procedure 
This is a painless outpatient procedure usually completed within 10-30 minutes. 

You lie on a flat, open, padded table. An “arm” in the shape of a "C" that houses the X-ray tube on one end and the detector on the other passes overhead. Images are sent to a computer with software that computes and displays the bone density measurements on a monitor. 

To look at the spine, the patient’s legs are supported on a padded box to flatten the back. To look at the patient’s hip, a foot is placed in a brace that rotates the hip inward. 

Your Results 
A radiologist analyzes the images and sends a signed report to your primary care or referring physician, who discusses the results with you. Small changes may be observed between scans due to differences in positioning. These changes are considered normal. 

Your test results are in the form of two scores: 

  1. T score -- The T score estimates your risk of developing a fracture. It shows the amount of bone you have compared with a young adult of the same gender with peak bone mass. A score above -1 is considered normal. A score between -1 and -2.5 is classified as having low bone mass. A score below -2.5 is defined as osteoporosis.
  2. Z score -- This number reflects the amount of bone you have compared with other people in your age group and of the same size and gender. If this score is unusually high or low, it may indicate a need for further medical tests.

About Your Bill 
You will receive two bills for your exam: 

  1. The hospital bill includes the cost to cover equipment, supplies and technical personnel
  2. The radiologist’s bill covers the professional reading of your exam
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