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DEXA Body Composition & Bone Density Scans

Dual energy X-ray absorptiometry (DEXA) gives us detailed information about your body. At UVA Health, we use DEXA for the following:

  • DEXA Body Composition scans to check your whole body if you're watching fitness or dietary changes, athletes, and anyone looking to improve their overall health. These scans allow us to create detailed reports about your body’s muscle, fat, and bone.
  • DEXA Bone Density scans test 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 

While a Body Composition DEXA will scan your entire body, a Bone Density DEXA might only target a certain area, such as your hip, spine, or forearm.

Both types of DEXA exams are performed on a small table. These scans only take a few minutes, and don't hurt or require anesthesia.

What Your DEXA Scan Can Tell You

You'll get different results based on the type of screening you received.

Body Composition Scan

We'll give you a report with your scan results. This information includes (but isn't limited to):

  • Total body fat percentage – details the percent of your body that is fat
  • Visceral adipose tissue (VAT) area – shows the amount of internal abdominal fat around your organs, with increased VAT associated with a higher risk of cardiovascular and metabolic disease
  • Appendicular lean mass to height ratio (ALMI) – shows the amount of lean mass (bone + muscle) in arms and legs compared to height, with low ALMI being associated with a higher risk for sarcopenia and poorer long-term health outcomes
  • Whole-body bone density – the average bone density for your entire skeleton; this can't detect osteopenia or osteoporosis but may show a need for further testing if the result is low

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 = Osteopenia, the first stage of bone loss 
  • Below -2.5 = 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.