Bone mineral density test
Bone Density Testing uses X-rays to measure the number of minerals in your bones, namely calcium. This test is especially important for people at risk for osteoporosis, especially women and the elderly.
The test is also known as dual-energy x-ray absorptiometry (DXA). This is an important test for osteoporosis, the most common type of bone disease. Osteoporosis is a disease in which bone tissue becomes thinner and weaker over time and leads to the cessation of fractures.
What is the purpose of the bone density test?
Your doctor may order a bone mineral density test to show that your bones are weak, that you are showing signs of osteoporosis, or that you are old enough to need preventive tests.
The National Institutes of Health (NIH) recommend that the following people undergo preventive bone mineral density tests:
- All women over 65
- Women under 65 are at increased risk of fractures.
Women are at risk of developing osteoporosis if they smoke or consume three or more alcoholic drinks a day:
- Chronic kidney disease
- Early menopause
- Eating disorder as a result of low body weight
- Family history of osteoporosis
- “Brittle fracture” (bone broken by normal activity)
- Significant loss of height (an indication of compression fractures in the spine)
- A sedentary lifestyle with low weight activities
How to prepare for the bone mineral density test
Bone density tests are easy, fast and painless. Virtually no preparation is needed. In fact, some simple versions of bone density tests can be done at your local pharmacy or drugstore.
If you’re having the test done at a medical centre or hospital, be sure to tell your doctor beforehand if you’ve recently had a barium exam or had contrast material injected for a CT scan or nuclear medicine test. Contrast materials might interfere with your bone density test.
How’s it performed?
The bone mineral density test is painless and does not require medication. You lie on a bench or table while the test is performed. The test can be done if you have the right equipment in your doctor’s office. If not, you may be sent to a specialized testing centre.
There are two types of bone density scans:
This test looks at your spine and hip bones. It tends to be more accurate. It also costs more. Central DXA stands for Dual Energy X-ray Absorptiometry.
This scan examines the bones of your forearm, wrist, fingers, or heel. This scan is generally used as a screening tool to find out if you need Central DXA. The test only takes a few minutes.
Risks of bone mineral density test
Bone Density Testing uses X-rays, there is a small risk associated with radiation exposure. However, the radiation levels from the test are very low. Experts agree that the risk of radiation exposure is much lower than the risk of not recognizing osteoporosis before suffering a fracture. Tell your doctor if you are pregnant. X-ray radiation can harm your fetus.
After the bone mineral density test
Your doctor will review the results of your test. The results, known as the T-score, based on a 30-year healthy bone mineral concentration compared to your own value. A score of 0 is considered ideal.
The NIH provides the following guidelines for bone density scores:
- Common: between 1 and -1
- Low bone mass: -1 to -2.5
- Osteoporosis: -2.5 or less
- Acute osteoporosis: -2.5 or less with fractures
Your doctor will discuss your results with you. Depending on your results and the reason for the test, your doctor may want to run an additional test. They will work with you to create a treatment plan to address any problems.