Person getting a DEXA scan

A DEXA scan is the most accurate and most commonly used method for measuring bone loss. It is the best way for doctors to diagnose conditions like osteoporosis or osteopenia, as well as assess a patient’s risk of suffering a bone fracture.

DEXA bone density exams are primarily recommended if you have x-ray evidence of vertebral fracture, family history of osteporosis or hip fracture, or experienced a fracture after only mild trauma.

If you have hyperthyroidism, hyperparathyroidism, type 1 diabetes, use medications that are known to cause bone loss or are a post-menopausal woman not taking estrogen, a DXA scan should be performed.

Woman using a mammogram machine

During a DEXA scan patients lie on their backs and the machine passes over them. It is a non-invasive, painless procedure that measures your bone density. The machine uses very low dose x-rays with differing energy levels that get directed at the bones being scanned. The images produced allow the radiologist to determine your bone mineral density. Fewer x-rays pass through denser bone. This information generates tells doctors the average density of the bone. A low score indicates that the bone is more prone to fracture and some material of the bone has been lost.

Do not take calcium, vitamin D or multi-vitamin supplements for at least 24 hours before your scan. If you are taking medications for osteoporosis or osteopenia, check with your doctor to confirm whether you should skip your dose on the day of your scan.

You must remove all jewelry and any other metallic objects such as hearing aids, jeans with metal zippers, body piercings and removable dental work.

Learn about Different Types of DEXA Exams

Vertibral Fracture Assessment

Vertebral Fracture Assessment scans the bones of the spine to see if any vertebrae have an abnormal shape. A VFA can be done on the same visit as measuring your bone density. It is particularly useful if you are at high risk for vertebral fracture but do not know if you have one. If you have become shorter with age, have stooped posture, previous fracture of any type as an adult, or unexplained back pain, you may have a vertebral fracture.

Prior vertebral fractures are a better predictor of future fractures than low bone mineral density alone and patients with vertebral fractures have an increased risk for future fractures. Two thirds of patients with vertebral fractures do not present with complaints of back pain, making this test extremely informative.

DEXA scans of spine

FRAX® tool

The FRAX tool was developed by the World Health Organization to evaluate the fracture risks of patients with low bone mass. The FRAX® models have been developed from studying population-based cohorts from Europe, North America, Asia and Australia. FRAX® can help to identify people who have a greater chance of breaking a bone as well as people who might benefit from taking osteoporosis medicine. The tool looks at a person’s age, family history, bone density and other factors to estimate the patient’s chance of fracturing a hip or another major bone within the next ten years. It can be used to guide treatment decisions in postmenopausal women, men over the age of 50, and people with low bone density.