A bone density test or a bone mineral density test determines whether you have a systemic skeletal disorder that causes bones to become weak and brittle, known as Osteoporosis. When you have Osteoporosis, your bones are more likely to break. It is a silent skeletal disorder, which means you may not experience any symptoms. Without a bone density test, you won’t be able to realise whether you have this condition until any of your bone breaks.
The bone density test estimates how many grams of calcium and other bone minerals are packed into each bone segment, using x-rays. Bones that are generally tested are in the hip, spine, and at times, the forearm.
If you have more bone minerals, the better it is, since it indicates that your bones are denser, stronger and less susceptible to break. Whereas, if you have fewer bone minerals, then your bone is more likely to break in a fall.
Your doctor may order this test to:
Osteoporosis is more common in women than men because women have thinner and smaller bones, but the condition can also affect men as well. Your chances of developing Osteoporosis increases as you age. No matter your gender or age, your doctor may order this test if you have:
Fractured a bone: Fragility fracture occurs when your bone becomes brittle, which results in fracture much more easily than expected. A strong sneeze or cough can also cause Fragility fractures.
Your doctor may also recommend having this test if you are:
Bone density tests are painless and only lasts for less than 15 minutes. You may not need any preparations virtually. But make sure that you inform your doctor if you have undergone a barium exam, nuclear medicine test or had contrast material injected for a CT scan recently. Contrast may affect the test results.
For at least 24 hours prior to the test, you should avoid taking calcium supplements.
Wear comfortable and loose clothes, and choose not to wear clothes having buttons, belts, or zips. Make sure that you don’t have any metal objects such as change, money clips or keys in your pockets.
Bone density tests are often done on bones more susceptible to break, such as:
The two different types of Bone density tests are:
For these diagnostic tests, you will be asked to lie down on a padded platform, and a mechanical arm moves over your body. It sends X-rays through your body and creates an image of your skeleton. The amount of radiation that you expose is much low in contrast to the amount of X-ray during a chest x-ray. The central DXA typically lasts about 10 to 30 minutes. The image will be sent to an expert who reads the result.
A small, movable machine is used to check bone density in the bones of your heel, finger and wrist. The instrument often used for the peripheral test is known as the peripheral devices.
Your results are expressed in two numbers- T-score and Z-score.
T-score: It compares the bone density of a healthy person of the same gender, with that of your bone density. The score can be normal, below normal, or level that can be a sign of Osteoporosis.
What your T-score indicates
-1.0 and above
-1.0 to -2.5
Low BMD, and it may lead to Osteoporosis
|-2.5 and below||
Z Score: It compares your bone mass with that of other people of your same gender, age and size. If your Z-score is less than -2.0, it indicates that when compared to other people of your age, you have abnormal bone loss is because of something other than ageing.
You’re expected to take this test every 1 or 2 years if you’re under medication for Osteoporosis. Your doctor may recommend taking this test, even if you’re not having this condition, particularly women during or after menopause.
A follow-up bone density test should be taken every two years. But your doctor may suggest testing more often if you’re taking certain medications or currently have certain medical conditions. The follow-up test will be compared with that of the earlier tests to know what change has occurred.
If Osteoporosis runs in your family, then you have an increased risk of developing Osteoporosis. The risk is more if your close relative, such as a parent or sibling has Osteoporosis. So you have to make sure that your diet includes calcium-rich food, and you’re engaged in a weight-bearing activity and should also avoid habits such as drinking alcohol and smoking.
No. Bone density tests are not the same as bone scans. They differ since bone scans are typically used to identify fractures, infections, inflammations cancer and other bone abnormalities, as well as normally need an injection of radioactive material beforehand.
There are various factors that can increase your chance of developing Osteoporosis. You’re more likely to develop Osteoporosis, if you’re having a thin build, and is postmenopausal. Your risk of getting Osteoporosis increases as you age. Besides that, certain medications and medical conditions also increase your chance of developing Osteoporosis.