Are you thinking of getting a DEXA (DXA) scan to find out your bone density? Do your research before you book your appointment, because not all DEXA scanners are created equal.
DEXA scans are one of the most exciting breakthroughs for bone health and the diagnosis of osteoporosis, but they can be used for so much more. DEXA – also referred to as DXA – is short for dual energy X-ray absorptiometry. DEXA scans are safe, accurate, painless and non-invasive.
How does a DEXA scan work?
Radiation (X-rays) go through your body during the DEXA scan. Some of the radiation is taken in by the bone and soft tissue and some travels through your body.
The DEXA scanner works out how much radiation is being passed through your bones by directing X-ray energy through the bone at a very fast rate, alternating from two different sources.
This allows the scanner to work out your bone density. It can also calculate how this measurement compares to other people who are the same age and sex, giving a good indication as to whether you’re at risk of conditions such as osteoporosis and osteopenia (when the bone thins - often a precursor to osteoporosis).
Why women need a DEXA scan
Loss of bone density affect a lot of people – and is completely asymptomatic until a person fractures a bone, or suffers from kyphosis (when the back becomes bent over – also known as Dowager’s Hump).
Kyphosis is often a result of spine or vertebral fractures, which gradually causes the spine to weaken. It's believed that at least 15% of European women over the age of 50 suffer from fractures.
Not all DEXA Scanners are the same
All DEXA scanners should have sufficient resolution and accuracy to identify the risk factors for osteoporosis. However, only a few clinics offer the more advanced diagnostic features and DXA consultants qualified to produce a comprehensive prognostic report allowing a more detailed and comprehensive analysis of your health.
A DEXA scanner equipped with ‘Advanced Body Composition’ capabilities will provide an accurate indication of total fat in the trunk region, which is an important diagnostic marker of health in its own right. When fat accumulates here, doctors know this is a risk factor for diabetes, heart disease and cancer.
Furthermore, if the DEXA machine has a CoreScan option, the instrumentation can identify whether this fat is stored around vital internal organs such as the liver, pancreas and intestines. Once you know your risk factors, you can discuss how to reduce your risk with lifestyle changes or medications.
Lead DXA expert, Professor David Reid says: ‘After the first vertebral fracture women (and probably men too), have a one in five chance of a second fracture within a year. Identifying people with, and at risk of, vertebral fractures is extremely important and it is now possible with the DEXA scanner.’
Once someone knows they are at risk of osteoporosis, getting the right treatment can produce a reduction in risk of up to 70%, by using lifestyle changes as well as supplements and prescribed medication.
The advantages of DEXA
Whichever type of scan you might choose, it’s worth remembering that a DEXA scanner is a powerful tool with a far lower radiation exposure than a CT scan, or even an X-ray.
It is safe to use for general screening, unlike CT scans. CT scans are not recommended unless there is known to be a specific clinical need for the test. This is because there is a small but real elevated risk of cancer.
A DEXA scan is a quick and easy procedure, unlike an MRI scan, where you have to lie very still in an enclosed space, which may trigger claustrophobia.
Your doctor can refer you for a DEXA scan, you can also self-refer yourself to a private clinic. Once the DEXA scan is completed, you will have a better understanding of your health, and peace of mind.
A condition in which the protein and mineral content of bone tissue is reduced, but less severely than in osteoporosis.Full medical glossary