What is a bone density scan?
A bone density scan, also known as a DEXA scan, is a low-dose X-ray diagnostic test that evaluates the amount of calcium and other minerals in the bones. The measurement indicates the strength and thickness of your bones (also known as bone density or mass).
As people become older, their bones get thinner. Osteopenia occurs when bones grow thinner than normal. Osteopenia puts you at risk for osteoporosis, a more serious bone disorder. Osteoporosis is a condition that causes bone thinning and causes fragility. Osteoporosis often affects older adults, with women over the age of 65 being the most affected. Fractures (broken bones) are more common in people with osteoporosis, particularly in the hips, spine, and wrists.
Other names: DEXA or DXA scan (dual energy X-ray absorptiometry), bone mineral density test or bone mineral density (BMD) test.
What is Bone Density Test used for?
A bone density test is used for the following:
- To diagnose osteopenia (low bone mass)
- To diagnose osteoporosis
- Predict the risk of future fractures
- See if treatment for osteoporosis is working
What is the need of a bone density test?
Most women over the age of 65 should get a bone density scan. Women in this age bracket are at a greater risk of bone density loss, which can result in fractures. One is also at risk of having poor bone density when:
- Have an extremely low body mass index.
- Older than the age of 50.
- Already had one or more fractures earlier.
- Have dropped half an inch or more in height in the last year.
- Are you a 70-year-old.
- Have a family history of osteoporosis.
Other risk factors are:
- Insufficient physical activity
- Cigarette smoking
- Excessive drinking
- Not consuming enough calcium and vitamin D.
What will happen during a Bone Density Test / DEXA Scan?
There are several methods for determining bone density. The most frequent and precise method is dual-energy x-ray absorptiometry, generally known as a DEXA scan. The scan is often performed by a radiologist.
During a Bone Density Test or a DEXA scan, the following events occur:
- A patient will be positioned on their back on a cushioned table.
- The patient will be requested to lie with their legs straight.
- The lower spine and hip will be scanned using a scanning machine. Simultaneously, another scanning equipment known as a photon generator will pass beneath you.
- Images from both devices will be merged and transmitted to a computer. The visuals on the computer screen will be seen by a healthcare practitioner.
- The patient must remain completely motionless while the machines scan.
A portable scanner called a peripheral DEXA (p-DEXA) scan may be used by a provider to test bone density in the forearm, finger, hand, or foot.
How to prepare for the test?
Before taking this test the doctor will give you instructions. It is possible that you will be asked to stop consuming calcium supplements 24 to 48 hours before your test, if you are taking any. You should also avoid wearing metal jewelry or clothing with metal things like buttons or buckles.
Is there any risk in the test?
A bone density scan utilizes extremely low levels of radiation. It is safe for all. However, it is not advised for pregnant women to take this test. Even small levels of radiation can be harmful to an unborn child. Inform your doctor if you are pregnant.
Understanding the results
T scores are commonly used to describe bone density levels. A T score compares the bone density measurements with the bone density of a healthy 30-year-old person. A low T score indicates that you have bone loss.
Your results may reveal:
- A T score of -1.0 or greater: This score is regarded as normal bone density.
- A T score of -1.0 to -2.5: This suggests you have a low bone density (osteopenia) and might develop osteoporosis.
- A T score of less than -2.5: This indicates that you are most likely suffering from osteoporosis.
If your findings suggest that you have poor bone density, your doctor will advise you on how to avoid additional bone loss such as:
- Increasing physical activity through exercises such as walking, dancing, and utilizing weight machines.
- Increasing your calcium and vitamin D intake
- Taking prescription medications to boost bone density.
Consult your doctor if you have any questions regarding your results or treatments for bone loss.
Important information about a bone density scan?
The most common method of measuring bone density is using a DEXA scan. However, your doctor may prescribe further tests to confirm a diagnosis or to determine if bone loss therapy is effective. These include calcium blood tests, vitamin D testing, and tests for some hormones.
