Bone density scan (DEXA scan)
A DEXA or a bone density scan requires a low dose of X-rays to view how dense, or strong the bones are in a human body. Osteoporosis, a condition often weakens bones, uses a bone density scan to diagnose. The scan is quicker, painless, and more effective in determining bone density than normal X-rays.
Bone density scans are for?
You might require a bone density scan if you are:
- Above 50 and having risks of developing osteoporosis
- Under 50 and have other risks factors like smoking or a previous broken bone
The results from the bone density require a fracture risk assessment to identify your chances of osteoporosis and breaking a bone. Osteoporosis doesn’t have any age limit, it can affect people at any age, but postmenopausal women are at high risk since their estrogen level declines after menopause. Osteoporosis doesn’t have symptoms until it breaks a bone—the denser your bones, the stronger and unlikely they will fracture.
Measuring bone density
Bone density scan requires a unique type of X-ray called dual-energy X-ray absorptiometry, where it passes through your body. Bones and soft tissues absorb some radiation while passing through your body. The detectors in the machine measure the radiation and send the results to a computer. Your results will require comparison with the average bone density level for your age, gender, and ethnicity.
How safe is a bone density scan?
Bone density scans are safe since they use way lower levels of radiation than standard X-rays, indicating the radiographer can stay in the room with you during the scan.
Although bone density scans and X-rays are safe, they are not recommended for pregnant women since they can affect the unborn.
Reviewed by – Dr. Priyanka, MBBS MD Microbiology
Page last reviewed: 16 JULY 2022