DEXA Scan (Bone Density Test)

Strong bones matter for your spine. Weak bones from osteoporosis can lead to painful compression fractures, and they can affect how well screws and implants hold after spine surgery. A DEXA scan is a quick, simple test that measures how strong your bones are.

DEXA stands for dual-energy X-ray absorptiometry. It uses two very low-dose X-ray beams to measure the mineral content, or density, of your bones, usually in the lower spine and hips. You simply lie on an open, padded table while a scanning arm passes over you.

A DEXA scan gives you a T-score, which compares your bone density to that of a healthy young adult:

• -1.0 or higher: normal bone density
• Between -1.0 and -2.5: low bone density (osteopenia)
• -2.5 or lower: osteoporosis

Dr. Grunch orders a DEXA scan:

• After a compression fracture, to look for osteoporosis and help prevent the next fracture
• Before a spinal fusion or deformity surgery, because bone strength affects how well screws hold and how well the bones fuse
• When a fusion has not healed as expected

If your bones are weak, treating osteoporosis before or after surgery can improve your results. Note: arthritis and old fractures in the spine can make the spine score look better than it really is, so Dr. Grunch also looks at the hip scores.

• Do not take calcium supplements (including multivitamins and antacids with calcium) for 24 hours before the test.
• Tell the center if you recently had a barium study or a CT or MRI with contrast, because you may need to wait one to two weeks.
• Wear comfortable clothes without zippers, buttons or metal, or plan to change into a gown.
• Tell them if you might be pregnant.
• Eat and take your other medicines as usual.

You lie on your back on a padded table, usually with your legs resting on a cushioned box. The scanner arm passes slowly over your lower spine and then your hip. You need to hold still, but there is nothing to feel. The test takes about 10 to 20 minutes.

There are no restrictions afterward. Your results will be reviewed with you, and if you have low bone density, Dr. Grunch may recommend calcium and vitamin D, bone-building medicine, or a referral to a bone health specialist or your primary care doctor.

A DEXA scan is one of the safest imaging tests. The radiation dose is very low, much lower than a standard chest X-ray.

Why does a spine surgeon care about bone density?

Weak bones raise the risk of compression fractures and can affect how well screws hold and bones fuse after spine surgery. Knowing your bone density helps Dr. Grunch plan safer surgery and prevent future fractures.

What is a T-score?

It compares your bone density to that of a healthy young adult. A T-score of -2.5 or lower means osteoporosis.

Do I need to stop my calcium before a DEXA scan?

Yes. Skip calcium supplements, including multivitamins and calcium antacids, for 24 hours before the test.

If Dr. Grunch has ordered a DEXA scan for you and you have questions, call 470-293-9800 or contact us. You can also ask general questions any time through our “Ask Us Anything” chat. For questions about scheduling, cost or arrival time for the test itself, call the imaging center where it is booked.

Related: All imaging and diagnostic tests · Compression fractures · Kyphoplasty

This information is for educational purposes only and is not medical advice. It does not replace individualized care from a licensed physician. Please talk to your provider about your symptoms and follow the instructions from your imaging center.