A DEXA bone density scan is a dual energy x-ray absorptiometry that uses x-ray technology to measure bone density. More specifically, it measures the distribution of lean muscle, fat, water, and bone in the body. If bone density is shown to be low, it may indicate a higher risk for osteoporosis or bone fractures. Additionally, more than other tests that measure body compositions, the DEXA is highly accurate and reproducible. 

What Does a DEXA Machine Do?

A DEXA machine is an imaging test that measures bone density (strength) and provides information that can be helpful in determining risk for osteoporosis or bone fractures. It uses x-ray technology to measure and calculate bone density. The DEXA machine can also measure other body composition such as muscle mass and body fat. Ultimately, it gives patients a fast, accurate, affordable, and safe way to measure bone health and other body compositions.

How Does a DEXA Bone Density Scan Work?

To begin, a technologist will have you lie on a DEXA x-ray table and will help to position you appropriately. The DEXA machine passes two extremely low dose x-ray beams at different energy levels through tissues in the body. The radiation is either absorbed by soft tissue, bone, or passes through the body. Special detectors in the DEXA machine calculate how much radiation passes through your bones and compares that number to the bone density of a healthy adult of the same age, gender, and ethnicity. The DEXA scan is a fast, accurate, affordable, and safe body composition test.

How Should You Prepare for a DEXA Bone Density Scan?

Preparing for your DEXA test does not require you to make too many changes to your regular routine. Continue eating, drinking, and taking medications as normal, unless otherwise specified by your healthcare provider. Upon arrival, your healthcare provider will have you fill out a questionnaire that indicates current health status, family history of broken bones, smoking history, and current medications. Some proactive steps you can take in preparation for your scan include:

• Discontinue taking any calcium supplements at least 24 hours before your scan (this includes multivitamins or antacids that are commonly used to treat heartburn)
• Wear loose-fitting clothing with no metal
• Tell your doctor if you are pregnant (medical experts recommend avoiding even low amounts of radiation while pregnant) 

Results and Follow-Up

The scan is an outpatient procedure that happens quickly and painlessly. The results of your scan will be sent to your primary healthcare provider. Once you meet with your healthcare provider, he or she will explain the results of your scan. 

The scan gives a T-score that shows whether your bone density is higher or lower than what a healthy person your same age, gender, and ethnicity might score. If there are any issues detected on the scan, your healthcare provider will discuss steps moving forward and will help create a treatment plan for you. 

Questions you may want to ask your healthcare provider if they have recommended a DEXA scan include:

• Why are you recommending this test?
• How long should I expect results to take?
• Do I need to schedule a follow-up appointment to discuss results?
• What should I do to prepare for this test?
• Where should I go for this test?
• Will I need other tests?
• Are there things I can do to improve bone health?