What is bone density testing?
Bone density testing—also known as dual-energy x-ray absorptiometry (DEXA or DXA)—uses x-ray images to assess bone mineral density (BMD). The absorption of dual x-ray beams by a patient’s bone is measured to determine the overall strength of the bone and the risk of fracture. The test is typically performed on the lower spine and hips.
What does bone density testing discover?
A bone density test is currently the only way to diagnose osteoporosis, a disease characterized by decreased bone density and quality. Osteoporosis and low bone density (osteopenia) increase the risk of bone fracture. Therefore, DEXA can be used to:
- Diagnose osteoporosis, either before or after a bone fracture
- Identify decreased bone density before you break a bone
- Assess your risk of bone fractures
- Monitor the success of osteoporosis treatment
When is bone density testing recommended?
Your healthcare provider will conduct a thorough health assessment to determine if you’re at risk for osteoporosis or decreased bone density. A bone density test may be considered if:
- Further bone testing is recommended based on the results of a screening test such as a peripheral dual x-ray absorptiometry (pDXA), quantitative ultrasound (QUS), or peripheral quantitative computed tomography (pQCT)
- You’ve lost height of at least ½ inch within a year
- You’ve lost a total height of 1 ½ inches
- You’ve had a break or bone loss in your spine
- You are a woman aged 65 or older
- You are a man aged 70 or older
- You break a bone after age 50
- You are a post-menopausal woman not taking estrogen
- You have risk factors such as rheumatoid arthritis, chronic kidney disease, liver disease, type 1 diabetes, or a thyroid condition
- You use medications that can cause bone loss, such as corticosteroids, anti-seizure medications, or high-dose thyroid replacement medications
How is bone density testing conducted?
Bone density tests are fast, easy, and noninvasive outpatient procedures. You will lay on a padded table while a mechanical imaging device passes over your body. You will be asked to stay still and perhaps hold your breath for a few seconds to ensure a clear image. The amount of radiation you’re exposed to is very small.
How are bone density test results interpreted?
Bone density test results are reported in T-scores and Z-scores:
Your T-score measures your bone mass compared to the bone mass of a healthy young adult of your gender.
- -1 and above: Normal bone density
- Between -1.1 and -2.5: Osteopenia (low bone density)
- -2.5 and below: Osteoporosis
Your Z-score measures your bone mass compared to healthy adults of your age, gender, weight, and ethnicity. If your score is significantly higher or lower than normal, you may need further medical tests.
If you meet any of the above mentioned recommendations for considering bone density testing, give Peninsula Radiology a call at (757) 898-8830. We’d love to help!