Dual energy X-ray absorptiometry (DEXA) measures the density of your bones. It tests to see if you have osteoporosis, a bone-thinning disease. This X-ray scan uses a small amount of radiation to take pictures of bones in the spine, hip and forearm.
How to Prep for a DEXA Scan
You should:
- Eat normally on the day of the scan.
- Wait up to 2 weeks before having a DEXA scan if you have had a barium study or if you have been injected with contrast dye for a CT scan or MRI.
- Wear loose, comfortable clothing. Do not wear clothing with metal zippers, belts or buttons.
- If there is any possibility that you are pregnant, let the staff know.
The DEXA Procedure
You might have a whole-body scan or of:
- Your hip and spine, also known as Central DEXA (this requires lying on a table)
- Your finger, hand, forearm or foot, also known as Peripheral DEXA, which uses a small device
Neither procedure hurts. These scans only take a few minutes.
How to Read Your DEXA Scan Results
Your scan results will show two types of scores. Together they provide a picture of your risk for breaking bones.
T Score
This number compares the amount of bone you have to a young adult of the same gender with peak bone mass.
- Over -1 = Normal bone density
- Between -1 and -2.5 = You might have osteopenia, the first stage of bone loss
- Below -2.5 = You may have osteoporosis
Z Score
This number compares the amount of bone you have to other people of your age group, gender and race.
A score below -2 is considered abnormal.
If the bone density scan shows you have osteoporosis, you'll want to tap the expertise of UVA Health. Learn more about our osteoporosis care.