If you are concerned about your bone health or at risk of conditions like osteoporosis, a bone density test can give you valuable insights. This simple and painless test helps detect early bone loss and guides your doctor in planning the right treatment to keep your bones strong and healthy.
In this article, you will learn everything you need to know about DEXA scans, from when to get tested to how to interpret your results and which risk factors to watch for.
What is a DEXA Bone Density Test?
A DEXA scan (Dual-Energy X-ray Absorptiometry) is a quick, painless, and non-invasive procedure that measures the mineral content in your bones. It primarily checks how much calcium and other minerals are packed into a segment of bone. This gives your doctor a clearer picture of your bone strength and helps assess your risk of osteoporosis.
When to get the Bone Density Test or DEXA scan?
You may need a DEXA scan if:
- You are a woman aged 65 or older.
- You are a man aged 70 or older.
- You are a postmenopausal woman.
- You are a man aged 50 to 70 with a risk factor.
- You have had a fracture from a minor fall or injury.
- You are taking medications for low bone density or bone mass.
- You have already been diagnosed with osteoporosis and are on pharmacological therapy.
- Your doctor wants to monitor the response to therapy.
How to diagnose Osteoporosis?
Your doctor may diagnose osteoporosis based on the following:
- A fragility fracture, particularly at the spine, hip, wrist, humerus, rib, and pelvis.
- A T-score smaller than or equal to -2.5. This indicates significant bone loss.
FRAX, or the Fracture Risk Assessment Tool, helps your doctor better understand your bone strength. This score calculates the 10-year risk of major fractures and is widely used in the United States.
How to read a Bone Density Test result?
Your results are interpreted using T scores and Z scores. Let’s see how.
- T-score compares your bone density with that of a young adult.
T-Score | Bone Health |
-1 and above | Normal |
Between -1 and -2.5 | Osteopenia or low bone density |
-2.5 or below | Osteoporosis |
- On the other hand, Z-scores compare your bone density with others your age, gender, and size. It’s useful for identifying potential secondary causes of your bone loss.
If you have a low bone density, consult your doctor for further treatment.
What are the Risk Factors for Osteoporosis?
You may be at higher risk if you:
- Are over the age of 65
- Had a previous fracture
- Have undergone long-term glucocorticoid therapy
- Weigh less than 58 kg
- Have a family history of hip fracture
- Smoke or consume alcohol regularly
- Belong to high-risk ethnic group
Other types of Bone Density Tests
Besides the commonly used DEXA scan, other bone density tests include peripheral DEXA, quantitative computed tomography, and quantitative ultrasound. These tests use different methods for assessing bone density and may be used in specific situations. The other bone density tests include:
- Peripheral DXA: This type of DXA scan includes portable equipment and is often used to measure bone density in the wrist and heel, making it easier for screening purposes.
- Quantitative Computed Tomography (QCT): QCT measures bone density in the spine or hip, providing a more detailed assessment of bone structure compared to DXA.
- Quantitative Ultrasound (QUS): QUS uses sound waves to measure bone density in the heel, forefoot, or distal tibia and is a non-invasive and radiation-free option.
Vertebral Fracture Assessment (VFA): While not a bone density test itself, VFA is a low-dose X-ray examination of the spine that can be included as a part of a DXA scan to assess for vertebral fracture, which can indicate an increased risk of fractures elsewhere in the body.
Precautions before the test
Before you go for a DEXA scan, keep these precautions in mind:
- Remove any metallic object like jewellery or a belt.
- Inform your doctor if you are on any medications.
- If you have recently had a CT scan or MRI, let your doctor know, as this may affect the test results.
Your bone health is a vital part of your well-being, especially as you grow older. A DEXA bone density test is a simple yet powerful tool to help you and your doctor take proactive steps in preventing fractures and managing osteoporosis.
If you fall into any of the risk categories or have concerns about your bone strength, don’t wait – talk to your doctor today about getting a bone density scan.
Frequently Asked Questions
What is normal bone density by age?
A T-score between -1 and +1 indicates that your bone density lies in the normal range.
What is the cost of a bone density test?
The bone density test price can vary from Rs. 600 to Rs. 3000 based on certain factors, including location, laboratory, and the test type. The price can be different for single-site scans, double-site scans, and three-site scans (hip, spine, and forearm).
Does a bone density test show cancer?
No, the DEXA scan does not detect the cancer. However, a bone scan can help identify cancerous spread to bones or evaluate bone health before or after cancer treatment.
At what age should a woman get a bone density test?
Women can get DEXA scans over the age of 65. Further, if you are 50 and above and have a family history of osteoporosis, you may go for a bone density test.
How often is a bone density test done?
For individuals with high risk, a bone density test or DEXA scan is repeated every 2 years, every 3 to 5 years for moderate risk, and 10 to 12 years for low-risk individuals.
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