Bone density scan (DXA scan)
What is a bone density scan?
A bone density scan checks the density (thickness) of your bones. If your bone density is low, you have a higher risk of a bone fracture.
This scan is also called a dual energy x-ray absorptiometry scan or DXA scan. It is sometimes called a bone mineral density scan or BMD scan.
See also
Who has a bone density scan?
Your GP or hospital doctor may arrange for you to have a bone density scan if:
- a fracture risk assessment shows your risk of fracture is intermediate (between low risk and high risk)
- you are under the age of 40 and have a significant risk of fracture – for example, you have had more than one fragility fracture, or have recently taken high doses of steroids
- you have had an early menopause and you have not had hormone replacement therapy (HRT)
- you are a woman with early invasive breast cancer and you:
- are going to start treatment with an aromatase inhibitor
- have had an early menopause due to your treatment
- are going to have treatment to stop your ovaries working
- you are a man with prostate cancer and you are going to start treatment with hormonal therapies that reduce testosterone levels – if you are on long-term hormonal therapy, you should have a DXA scan every year
- you are taking steroids.
How the scan is done
During the scan, you lie on your back on a couch while a scanner moves above your body. The amount of radiation from a bone density scan is much less than from a normal x-ray.
The scan only takes a few minutes and is painless. It is important there are no metal fastenings such as zips in the area being scanned. You may be asked to put on a hospital gown for the scan.
Bone density scan results
The results of the scan will show whether you have:
- normal bone density
- low bone density (osteopenia)
- osteoporosis
Your scan results are reported as a number called a T-score. Your T-score is your bone density compared with the bone density of an average healthy young adult of your gender. Your T-score is the number of units that your bone density is above or below the average.
What your T-score means
|
T-score |
|
|
-1 and above |
Your bone density is normal. |
|
Between -1 and -2.5 |
Your bone density is below normal. Doctors call this osteopenia. |
|
-2.5 and below |
This score suggests you have osteoporosis. Your bone density is low and your bones are at higher risk of fracture. |
After a bone density scan
If the scan shows you have low bone density your GP may advise you to:
- take a drug treatment to protect your bones
- eat a healthy, balanced diet
- get enough sunshine (if this is possible)
- keep physically active.