WHAT IS BONE DENSITOMETRY?
A bone density scan, known as bone densitometry or DEXA, is a radiology study to measure bone loss. This quick, painless study is common for the lower back and hips and areas affected by osteoporosis. Most commonly, bone densitometry is used to determine a patient’s risk for bone fracture. Additionally, bone densitometry can measure metallic hardware in the body.
Bone mineral is measured with a T score. A T score shows the amount of bone patients have compared to an adult of the same age and gender. Scores above -1 are normal. A score between -1 and -2.5 is called osteopenia, the first stage of bone loss. A score below -2.5 is defined as osteoporosis.
What is bone densitometry used for?
Bone densitometry is commonly used to diagnose osteoporosis. While osteoporosis usually affects post-menopausal women, it can also affect men. Osteoporosis involves a gradual loss of calcium, which causes bones to thin. When bones begin to thin, they are more likely to break. Bone density scans can help determine a patient’s risk for fracture. Additionally, bone densitometry can be used to track the body’s response to osteoporosis treatment after diagnosis.
Bone density testing is recommended for:
- Post-menopausal women over 60, who have risk factors for developing osteoporosis
- Patients with a personal or maternal history of hip fracture or smoking
- Post-menopausal women who are tall (over 5 feet 7 inches) or thin (less than 125 pounds)
- Men and women who have hyperparathyroidism
- Men and women who have taken medications known to cause bone loss for an extended period
How do I prepare for a bone density scan?
Bone densitometry is a quick and painless test that does not require much special preparation. However, there are a few things to keep in mind before your exam:
- Refrain from taking calcium supplements for at least 24 hours before your study
- Wear comfortable clothing and avoid garments that have zippers, belts or buttons made of metal /li>
- Let your technologist know if you’ve recently had a barium examination or have been injected with a contrast material for a CT or radioisotope scan
- Let your technologist know if there is a possibility you are pregnant
What should I expect during bone densitometry?
Bone densitometry is a non-invasive procedure. The study typically takes between 10 and 30 minutes, depending on the type of study and what part of the body needs to be examined. To begin the exam, you’ll lie on a padded table with a detector (an imaging device) above. You’ll be asked to remain as still as possible during the procedure—movement can blur the image, decreasing its quality. The results of a bone density examination are interpreted by a radiologist and forwarded to your doctor.