Ask the doctor: Which bone density test should I have?
Q. My doctor has recommended a bone density screening, but the medical center with the full-body scanner is a 45-minute drive from my house. A health fair at a neighborhood church offers a bone density test using a foot scanner. Would that be as accurate?
A. The foot scan is called a quantitative ultrasound, and it usually measures the bone density of the heel bone.
It appears to be at least as good as clinical risk factors—such as older age, family history of bone fractures, low body mass index, smoking, corticosteroid use, and excessive alcohol consumption—for identifying people at high risk for osteoporosis.
However, there are limitations to ultrasound. It doesn't reliably exclude or confirm osteoporosis that would be found using a DEXA scanner, and there are no established criteria for diagnosing osteoporosis and recommending treatment based on ultrasound. If ultrasound finds that you're at high risk for a fracture, you'll need a DEXA scan to determine whether you need treatment.