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What to Expect from a Bone Density Test

What to Expect from a Bone Density Test
If your doctor recommends a bone density test (BDT), also called a DEXA scan, you may wonder what’s involved. Do you have to prepare for a BDT? And after you get your results, what do they mean? Will you have to take medication? Learn here.

As women (and men) age, and their hormones diminish, they’re at risk for rapid bone loss that can raise the odds that they’ll suffer a fracture. To keep tabs on your bone health, your doctor may recommend a bone density test (BDT), also called a dual-energy-X-ray absorptiometry (DEXA) scan.

Even though a BDT is a simple test, you may be nervous if you’ve never had one before. You may also be anxious about what your results could mean.

At Mass Medical Imaging in Lake Forest, Illinois, our expert doctors, Joseph Calandra, MD and Karen Mass, MD, want to protect your bone health. They may recommend a BDT if you’ve recently had a fracture, are nearing or in menopause, or have other risk factors for bone conditions such as osteopenia and osteoporosis.

What can you expect at your first BDT? Following is a brief rundown.

What a BDT measures

Your doctors want to get a good look at the interior of your bones to find out how dense and strong they are. Even though you may think about bones as being hard and dry, healthy bones are living tissue that’s constantly renewing itself. 

When you’re young, you quickly and easily replace old, dead, or dying bone cells with fresh new ones. But after age 20, your bone replacement starts to slow down. You usually reach peak bone mass at age 30 and from then on, your bone mass begins to decline.

Everyone starts out with a different level of peak bone mass. If you’re small-framed, Caucasian, or Asian, you probably had less bone mass to begin with. A BDT determines if you’re in the process of losing too much bone (i.e., osteopenia) or have already developed osteoporosis, which increases your risk for fracture.

How to prepare for a BDT

For the most part, there’s not much to do in preparation for your BDT. It’s a totally painless and fast type of X-ray. However, you shouldn’t take a calcium supplement for 24 hours before your test. You should also avoid a contrast-dye imaging study the week before your BDT, because it could skew your results.

Leave your jewelry at home and dress in comfortable, loose clothing the day of your test. Try not to wear anything with a zipper or metal buttons, either, or you may need to change into a hospital gown.

What happens during your BDT

When you get a BDT, you simply lie in place on the exam table. In most cases, you’ll be in your normal street clothes.

The technician then positions the X-ray scanner above the bones that your doctor wants to evaluate.The technician may scan your:

  • Lower spine
  • Hips
  • Forearm and wrist

Even if more than one area is scanned, the whole BDT only takes 10-20 minutes. You’re free to go home directly afterward.

What your results mean

When your results are ready, you meet with your doctor, who explains what they mean. The BDT has two measurements that evaluate your bone health: A T-score that compares your bones to healthy, young bones; and a Z-score that compares your bones to other women of your age and ethnicity.

Your scores are either normal, show osteopenia, or demonstrate that you’ve already developed osteoporosis:

  • Normal: T-score of -1 and above 
  • Osteopenia: T-score between -1 and -2.5 
  • Osteoporosis: T-score of -2.5 and below 

When your Z score is abnormally low, we may order other tests to find out why. You may have an underlying medication condition that’s affecting your bone health. 

If your T score is low, we may recommend a variety of lifestyle changes, supplements, and even medications to strengthen your bones and prevent further bone loss.

Are you ready for your BDT? Contact us for a bone scan today by calling our friendly team or using our online appointment form.