Dual-energy x-ray absorptiometry (DXA) is the most accurate scan for diagnosing osteoporosis and other bone fractures.
A DXA (DECK-sa) scan is a non-invasive procedure used to measure bone density, as well as mineral content in other parts of the body, including the:
- Hip
- Spine
- Wrist
- Fingers
- Heel bones
DXA scans are the most accurate ways to diagnose:
- The first stages of bone loss (osteopenia)
- Osteoporosis (PDF)
- The thinning of bones that can lead to bone fractures in aging men and women
The benefits of a dual-hip DXA scan
Compared to regular x-rays, our state-of-the-art DXA technology offers more precise images, allowing for more accurate diagnoses.
More precise images
DXA scans:
- Show abnormalities before an x-ray would ever pick them up
More accurate diagnoses and earlier treatment
- Are the most accurate tests available for diagnosing and treating osteoporosis and other bone fractures
- Help doctors treat bone loss early, so prevention of the disease is possible
Less radiation
- Require less radiation exposure than the body normally gets in a day from natural radiation
- Leave no remaining radiation in the body after the scan
- Do not require anesthesia
Preparing for your DXA scan
Considerations
You should not have a DXA scan if you:
- Are pregnant or think you are pregnant
- Have had another x-ray or nuclear scan with contrast media in the last 7 days, such as:
- Barium enema
- Upper GI
- Some CT scans
- Thyroid study
48 hours before the test:
- Stop taking calcium supplements (if you normally take them)
The day of your test:
- If you take medicines for osteopenia or osteoporosis, do not take them
- Eat normally
- Wear loose, comfortable clothing
- Avoid wearing metal jewelry or clothing with metal zippers, belts, or buttons
What to expect during your dual-hip DXA scan
A DXA scan is a non-invasive test that usually lasts between 10 and 30 minutes. DXA scans require you to lie very still for the duration of the scan, in order to produce clear, crisp images.
Before the test begins, be sure to:
- Tell the technologist if you have had any hip or back injuries
- Remove any kind of metal jewelry
Next:
- Your technologist will position you lying down on a table, with the scanner above you.
- A machine will pass over your body and take measurements of your bone mineral density (BMD) by sending a thin, invisible beam of low-dose x-rays through your bones. The amount of radiation is very small, less than 1/10 the dose of a standard chest x-ray.
- A picture of your skeleton will be made, based on how much the x-rays have changed after passing through your bones.
- Your BMD will be matched with average BMD values for your age and gender, allowing the doctor to properly determine your treatment plan.
After your dual-hip DXA scan
A board-certified radiologist studies your scans and reports the results to your doctor. Then, your scans are delivered to your doctor via our state-of-the-art computer system.
If your images are ever needed, they can be accessed by any UPMC hospital or facility at any time of the day or night.
Your test results
The results of your DXA scan will be interpreted in the form of two scores: T score and Z score.
T score: This number shows the amount of bone you have, compared to a young adult of the same gender with peak bone mass. It's used to estimate your risk of developing a fracture.
A score:
- Above -1 is considered normal
- Between -1 and -2.5 is classified as osteopenia, the first stage of bone loss
- Below -2.5 is defined as osteoporosis
Z score: This number reflects the amount of bone you have, compared to other people in your age group and of the same size and gender.
If your Z score is unusually high or low, it may indicate a need for further medical tests.
