Bone density scanning (DEXA or DXA) at Wessex Hospital

Why might I need one?

Your doctor might suggest a DEXA scan if:

• you've broken a bone
• you have symptoms of a spinal fracture such as height loss, a change in posture or unexplained back pain
• you have risk factors such as your age or a family history of osteoporosis.

You may be more likely to need a scan if you're a woman over 65, a man over 70, or under 50 with other risk factors such as smoking or a previous broken bone. Long-term steroid tablets and certain other conditions can also increase your risk.

What are the benefits of having a DEXA scan?

Having your bone density checked means problems can often be picked up before you break a bone, since osteoporosis itself doesn't cause symptoms early on. If your results show you're at higher risk, this can lead to advice or treatment that helps strengthen your bones and lowers your chance of a fracture in future.

Are there different types of scan?

A DEXA scan usually looks at your hip and spine, the two most common places for fractures, though sometimes your wrist or forearm is scanned too.

This is a different test to a 'whole-body bone scan', which uses a different technique to check whether a cancer has spread to the bones, rather than measuring bone density.

How do I prepare for a DEXA scan?

On the day, wear clothes without metal, such as zips, buttons or underwired bras, as this can affect the scan images. A hospital gown will be available if needed.

You can eat and drink normally, and take your usual medicines. Bring a list of your medicines with you. If you take a calcium supplement, avoid taking it for 24 hours before your scan. You may also be asked to fill in a short questionnaire about your medical and family history.

What happens during the scan?

A DEXA scan usually follows these steps:

1. You'll be weighed and measured for height, and may be asked a few simple questions
2. You'll lie on your back on a firm, flat table
3. A technician will help position your body, sometimes using foam blocks under your legs
4. A scanning arm passes slowly over your body, usually over your hip and then your spine, taking images as it goes – you’ll need to lie still while this happens, though you won't feel anything.

The whole appointment usually takes around 20 to 30 minutes. You don't go into a tunnel, and there's no injection involved.

What happens after the scan?

You'll usually be able to go home straight after the scan. Results normally take around 3 weeks to come through, and you might be told them by letter, text, email or phone call, or sometimes at a face-to-face appointment. If you haven't heard back in the time you were told to expect, contact whoever referred you for the scan.

Your bone density result is usually combined with other information, such as your height, weight and other risk factors, as part of a fracture risk assessment.

Depending on the results, you might be offered an osteoporosis medicine, lifestyle advice, further tests, or a follow-up scan in future, usually after 2 to 5 years, or sooner if you have ongoing risk factors.

What are the risks?

DEXA scans are very safe and use a much lower dose of radiation than a standard X-ray, similar to around 3 days' worth of the radiation we're all naturally exposed to in everyday life. There's no pain and no known side effects from the scan itself.

Bone density scans and X-rays generally aren't recommended if you're pregnant, so tell the department if you are, or think you might be, so your appointment can be rearranged.