Bone densitometry (DEXA) scanning

What is bone densitometry (DEXA) scanning?

Bone densitometry scanning measures the density of bones and is used to check for signs of osteoporosis, a condition where the bones become weak and prone to fracture.

The most accurate and reliable way to measure your bone density and find out if you have osteoporosis, or if you may develop it in the future, is to have a DEXA scan, which scans your bones. DEXA stands for dual energy X-ray absorptiometry.

What are the benefits of bone densitometry (DEXA) scanning?

Scanning for osteoporosis is the only way to find out if you have osteoporosis or if you are likely to develop it. Steps can then be taken to help prevent its development. Osteoporosis usually has no symptoms – the first sign is often a break or fracture. You should be scanned if you are at risk of osteoporosis.

You have a greater risk of developing osteoporosis if you:

  • Have already suffered a break or fracture resulting from a minor bump, strain or fall
  • Are over 50
  • Have gone through early menopause (before the age of 45)
  • Have had your ovaries removed (before the age of 45)
  • Have a history of missed periods
  • Are on long-term corticosteroid medication
  • Have a family history of osteoporosis or fractures
  • Have low levels of calcium and vitamin
  • Have digestive disorders that affect nutrient absorption

The procedure

The DEXA machine is used to scan the bones in your lower back and hip, and sometimes your forearm. These are the bones most prone to fracture if you have osteoporosis. The scan will measure the density of bone and tissue separately.

You will be asked to lie flat on a couch and stay still while the different parts of your body are scanned. The procedure is painless and takes around 20 minutes.

The information from the scanner is sent to a computer to be processed and you will be given a T-Score, which compares your bone density to that of healthy bones.

Results of the scan

  • Between 0 and -1 means no action is needed
  • Between -1 and -2.5 means you have osteopenia. This result isn’t serious, but it means your bone density is lower than normal and you may be more likely to develop osteoporosis in the future
  • Below -2.5 means you have osteoporosis, and you will probably be offered treatment by your doctor

The following can help build healthy bones:

  • Eating calcium-rich foods including dairy products and green, leafy vegetables
  • Getting enough vitamin D in your diet, this is essential for absorbing calcium. Vitamin D is found in foods such as milk, eggs and oily fish
  • Bone-building exercise such as jogging, aerobics, tennis, dancing, brisk walking and weight lifting, and low-impact exercise such as swimming, gardening, walking or playing golf 
  • Avoiding smoking as this can reduce your bone density
  • Avoiding drinking alcohol as this damages our skeleton and increases the risk of fracture
  • Avoiding drinking too much caffeine as this may affect the balance of calcium in the body.

For more information, and if you have any queries about the procedure, speak to your consultant. Continue your normal medication unless you are told otherwise. Always check your doctor first before taking up any vigorous exercise.

The future

Further scans can be taken a year or two later to see if the density of your bones is improving or getting worse. If the scan shows you have osteoporosis, you can still make the above lifestyle changes to reduce your risk of fracture. Drug treatment is also available to help manage the condition. For details of side effects, speak to your doctor.

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