Bone densitometry (DEXA)

A dual-energy x-ray absorptiometry scan (DEXA), or bone density scan, is a special type of x-ray that measures bone mineral density (BMD). It provides information about bone strength or fragility and the risk of fractures or broken bones. A higher density generally indicates a lower risk of fracture.

The spine and one or both hips are routinely scanned; some machines also routinely evaluate the forearm. The forearm might also be scanned if either the hip or spine is unavailable (usually due to surgery). As any condition affecting bone density tends to affect the whole skeleton, a snapshot of a few sites is sufficient to establish the overall bone density. BMD has been shown to be the best way of predicting the risk of fracture.

You might be referred for this test if you have:

• a medical condition that could weaken your bones
• had recent fracture after a minor injury or fall, that would not have broken this bone in other people
• an x-ray image or picture taken for another reason which has shown that the vertebrae in your spine are weakened and losing height.

The most common cause for this is osteoporosis, which is a common condition that increases with age. It is a major cause of weak bones, causing fractures resulting from minor injury, which is preventable with treatment. Osteoporosis, in the absence of fracture, has no symptoms. A number of medical conditions and medications can increase bone loss, making it important to diagnose osteoporosis early, to prevent fractures from occurring. The DEXA scan measures the bone mineral content and provides information to your doctor as to whether you have lost a small amount of bone (osteopenia) or a more significant amount (osteoporosis), compared with a young normal population, and people of the same age and sex as you. This informs your doctor about your risk of having a fracture, and assists in monitoring bone loss and in planning any preventative therapy or medical treatment.

Your doctor will receive a written report on your test as soon as is practicable.

It is very important that you discuss the results with the doctor who referred you so they can explain what the results mean for you.