What Happens During A Bone Density Test?

By Gwen Dawkins

Have you had a DEXA or bone density test? Women’s health professionals advise getting one at approximately age 65 (men at age 70) and older to track bone strength/density over time. But, of course, if you’ve had broken bones or a family history of osteoporosis, sooner is better. Because I already know that I have osteoarthritis in my knees and have lost at least one and a half inches in height, I got mine at age 58. And guess what? I already have mild bone loss.

I had a DEXA Scan a few weeks ago. It’s just another one of those things I hadn’t gotten around to doing. But it was quick, easy and painless.

The X-ray machine arm hovers over your lower spine and hips, beaming low level radiation to measure bone density in the center of your skeleton. Other bones such as knees, legs and arms may be scanned as well.

I was advised to wear sweats or similarly loose clothing (without metal such as zippers or embellishments). The radiologist told me to lie flat on my back and hold still while the scanning arm slowly passed over my body. In my case, they scanned my lower body only. I was in and out in 10 minutes.

Gwen’s Test Results

Below is the report I received after the test:

Impression: bone density, Osteoarthritis of both knees, unspecified osteoarthritis type

(The test compares the patient’s results to a healthy young adult with normal bone density.)

COMPARISON:

Region BMD Young-Adult 

DESIGNATION

g/cm2 T-score

FINDINGS:

L1-4 1.130 -0.5 

normal

Femoral Neck-R 0.855 -1.3 

osteopenia

The ten-year probability for a major osteoporosis-related fracture is 7.1% 

and the ten-year probability of a hip fracture is 0.5%

IMPRESSION: Osteopenia

GENERAL OSTEOPOROSIS INFORMATION

The T-score represents the standard deviation in bone mineral density from the mean bone mineral density of a young adult population, while the Z-score represents the standard deviation from an age-matched population. Osteopenia (or low bone mass) is defined as a T-score between -1.0 and -2.5, and osteoporosis is defined as a T-score less than or equal to -2.5.

Bone mineral density begins to decline after peak bone mass is achieved (age 25-30), and bone mineral loss accelerates with aging, especially after menopause. Therefore, a decrease in bone mineral density of 2% per year is considered normal in patients over the age of 50.

What My Doctor Said

Basically, my spine appears fine. My doctor said I should not have lost any height — but I have! She told me my height reduction may be a result of cartilage loss around my knees and osteopenia in my hips. Supposedly, she could tell that I was a long-time runner based on my test results. She advised me to continue with my weight-bearing exercises such as weightlifting and hiking. I should also continue my Vitamin D supplementation, to help with calcium absorption, which should primarily come from my diet.

For cash-paying patients, a DEXA scan typically costs $125 – $250. For patients covered by healthcare, the co-pay is generally $15-$50. This test is also typically covered by Medicare after age 65.