Osteoporosis is a disease that causes bones to become more fragile and more likely to break. Bone density testing is sometimes called a DEXA test and is used to determine how much bone loss you may have.
The National Osteoporosis Foundation suggests bone density testing if:
- You’re a woman age 65 or older.
- You’re a postmenopausal woman under age 65 with one or more risk factors for osteoporosis.
- You’re a man age 70 or older.
- You’re a man between age 50 and 70 with one or more risk factors for osteoporosis.
- You’re older than age 50 and you’ve experienced a broken bone.
- You’re a postmenopausal woman and you’ve stopped taking estrogen therapy or hormone therapy.
Research hasn’t yet determined the optimal interval for repeat bone density tests, or the right age to stop testing. However, two or more years may be needed between tests to reliably measure a change in your bone density. Your doctor can recommend the best testing interval for you based on your personal medical history and osteoporosis risk factors.
Osteoporosis risk factors
- Age- which increases your risk of osteoporosis because bones become weaker as you age.
- Ethnicity- for instance, women who are white or of Southeast Asian descent have the greatest risk of osteoporosis, and African-American and Hispanic men and women have a lower, but still significant, risk of the disease.
- Low body weight, or under 125 pounds (56.7 kilograms) if you’re of average height.
- A personal history of fractures after age 40.
- A parental history of osteoporosis or hip fractures.
- Using certain medications that can cause bone loss, especially steroids.
How Long Will It Take?
Dexa scans themselves generally take less than 15 minutes to perform but plan on being at our imaging facility for at least 30 minutes to ensure that we obtain a complete history and all pertinent information.
What Does a DEXA show?
Two separate x-ray beams evaluate the bone in your spine and hip. The amount of x-ray that passes all the way through the bone is measured and used to determine whether you have osteoporosis and how bad the disease is. The higher your bone mineral content, the denser your bones are. And the denser your bones, the stronger they generally are and less likely to break. Based on these findings, your doctor can then decide how best to proceed. Once treatment begins, you will likely get a DEXA scan every other year to assess how well the treatment is working.
Doctors use bone density testing to:
- Identify decreases in bone density before you break a bone and to determine your risk for fractures.
- Confirm a diagnosis of osteoporosis if you’ve experienced broken bones.
- Monitor osteoporosis treatment.
Bone density tests are not the same as bone scans/ Nuclear Medicine scans. Bone scans require an injection beforehand and are usually used to detect fractures, cancer, infections and other abnormalities in the bone.
Preparing for your Dexa
X-rays are potentially harmful to a developing fetus, so please inform your doctor and the technologist if you think you may be pregnant.
Be sure to tell your doctor beforehand if you’ve had recent oral contrast or nuclear medicine tests. These tests require an injection of radioactive tracers that might interfere with your bone density test.
What to expect?
- The examination is painless and there is no preparation for Bone Density.
- It is best to wear sports bras and elastic waistbands if you would like to avoid changing into a gown.
- You will be asked to lie still on a table and will see the arm of the DEXA scanner above you.
After the Procedure
- After the examination is completed, the images are stored in a computer system called PACS (Picture Archiving & Communications System). We typically have the patient wait until all images are reviewed to make certain no additional imaging is needed. Most referring doctors can access these images online and review them with you in their office.
- Our Board Certified Radiologist will review your images and have the results faxed to your referring physician promptly. The results from a bone density test can let you know how your fracture risk compares with that of other people of your age, sex and other similar characteristics.
Your bone density test results are reported in two numbers: T-score and Z-score.
- T-score- is your bone density compared with what is normally expected in a healthy young adult of your sex. Your T-score is the number of units — standard deviations (SD) — that your bone density is above or below the average.
- Z-score- is the number of standard deviations above or below what’s normally expected for someone of your age, sex, weight, and ethnic or racial origin. This is helpful because it may suggest you have a secondary form of osteoporosis through which something other than aging is causing abnormal bone loss.
Keep in mind that these scores apply mostly to white postmenopausal women, who tend to have lower bone density as compared with other racial groups and men. Interpretations may vary if you’re a woman of color or a man.
- You may obtain a copy of your results from your referring physician. Only the patient can physically acquire them from our Imaging Center after showing proof of identity. This is in effort to protect not only your privacy but to reduce medical identity theft.
