Bone Mineral Density Test: Purpose, Procedure, Normal Range, Results & Uses

Understanding the Bone Mineral Density Test and Its Importance for Bone Health

The Bone Mineral Density (BMD) test is an easy-to-follow imaging test to assess the strength of your bones. This test is one of the most reliable methods for detecting osteoporosis and the risk of fracture.

The BMD test is completely painless with no special preparation beforehand. Thus, doctors suggest it particularly for postmenopausal women, elderly adults, and individuals taking medications on a long-term basis. This article explains the bone mineral density test procedure, purpose, insurance coverage and more.

What is the Bone Mineral Density Test?

The Bone Mineral Density (BMD) test evaluates the density and strength of your bones. This test also measures how much minerals and calcium are present in a bone segment. Denser bones are much stronger and less likely to break. It allows doctors to diagnose and monitor conditions relating to:

1. Osteopenia
2. Osteoporosis
3. Risk of fracture in bones

The common method for this test is Dual-Energy X-ray Absorptiometry (DEXA or DXA), which provides accurate results with minimal radiation exposure. This test is typically carried out on the hip, spine and forearm, as these areas are more prone to fractures.

For instance, a 65-year-old woman with a history of fractures in her family can undergo a BMD test to find out if the bones have become weaker with age. Results are obtained as a T-score, which provides a detailed comparison of your bone density to that of a healthy young adult.

Why is the Bone Mineral Density Test Done?

Doctors typically suggest a BMD bone test for the following reasons:

1. Disease Diagnosis: To confirm osteoporosis or osteopenia among patients experiencing bone fractures or pain in bones.
2. Monitor Ongoing Treatment: Helps to track the effectiveness of osteoporosis medications well by comparing bone density reports over time.
3. High Risk Individuals Evaluation: Beneficial for evaluating women aged 65 and above, men aged 70 years and above, and postmenopausal women under 65 years with risk conditions.
4. Detect Abnormalities: Identifies bone loss at an early period before an occurring fracture, and thereby allows for on-time medical intervention.
5. Preventive Health Check-ups: Enable learning of bone density reading among middle-aged This also enables them to monitor bone conditions and changes (if any) in the future.

What are the Symptoms or Conditions that Need this Bone Mineral Density Test?

Bone loss is often called a "silent disease" because it causes no symptoms. Your doctor suggests a Bone Mineral Density test if you have the following symptoms:

1. Unexplained Fracture: Bone fracture due to a minor fall or while performing everyday activity, causing little to no trauma.
2. Loss of Height: Loss of height (typically more than 1–1.5 inches or 2–4 cm) over time may indicate vertebral fractures or bone loss.
3. Chronic Pain in the Back: You might face pain consistently due to a collapse or fracture in the vertebrae.
4. Early Menopause: There occur major changes in hormones that speed up the loss of bone among women.
5. Long-term Use of Steroids: Taking corticosteroids for a prolonged period results in weak bone structure over time.

How is the Bone Mineral Density Test Performed?

The bone mineral density test is a simple and painless process where you need to lie back on the X-ray table to let a portion of your body be scanned. Here is what you need to know more:

1. Positioning: You need to lie flat on your back on the X-ray table. Stay on the table throughout the scan to prevent blurred images.
2. Scanning Arm: A large scan arm goes over your body slowly. This reflects a narrow beam of X-rays at a low dose through the area under scan.
3. Scanned Area: The forearm (distal radius) may be scanned when hip or spine measurements are not possible or in conditions such as hyperparathyroidism, where cortical bone is preferentially affected.

Most importantly, there is a detector inside the scanning arm that evaluates X-rays passing through and generates an image. This scan usually takes around 10 to 20 minutes. After the test, you can return home immediately.

What is the Preparation Before the Bone Mineral Density Test?

You might be wondering: How to prepare for the BMD test?

Preparing for the bone mineral density test procedure is simple. Before undergoing the bone mineral density test, your doctor may advise:

1. Avoid Calcium Supplement: At least 24 hours before the test, avoid taking any calcium supplements. These supplements might interfere with bone density readings.
2. Comfortable Dressing: On the particular day of the scan, prefer wearing loose and comfortable clothes. Also, do not wear garments with buttons or zippers, as metals might pose problems during imaging.
3. No Fasting: Unlike other medical tests, you need not fast. You can eat or drink before taking a BMD test.
4. Inform Doctor: Consult a doctor and share your complete medical history, which includes recent surgery, fractures in previous times, or imaging tests such as CT or dye procedures.

What is the Normal Range or Expected Results of Bone Mineral Density Test?

Note: The test values might vary slightly depending on the condition of the patients and the laboratory.

Results Interpretation

The bone mineral densitometry report provides you with two types of scores: the T-score and the Z-score.

1. T-score

The T-score provides a detailed comparison of your bone density with that of a healthy and young adult. It also showcases how high or low your bone density is when compared with the standard value.

Here is the detailed interpretation of the results:

• -1 and above: Implies a healthy bone density.
• Between -1 and -2.5: Implies osteopenia, which says your bone density is quite below the standard level and might lead to osteoporosis.
• -2.5 and below: Implies osteoporosis, which is a condition relating to weakening of bones and raises the risk of fracture.

2. Z-score

The Z-score provides a detailed comparison of your bone density considering the age, weight, sex, and racial or ethnic background. If there is a high Z-score or lower than the expected range, your healthcare professional might suggest other tests to find the underlying cause.

What are the Risks or Side Effects of a Bone Mineral Density Test?

The bone mineral density test is helpful, but it possesses certain limitations:

1. Different Methods of Testing: Tests measuring bone density in the hip and spine show more accuracy than checking the bones in the fingers, forearm, or heels.
2. Spinal Conditions: A bone mineral density test might not provide accurate results if you have a history of scoliosis, arthritis, or even past surgeries.
3. Exposure to Radiation: The bone density test involves minimal X-ray radiation. The exposure might be significantly low, but this test is not recommended during pregnancy.

Also note that the bone density test reveals your low bone density, but it does not state the main cause behind it. Your healthcare professional might suggest other tests to find more.

What are the Benefits of Bone Mineral Density Test?

Here are some benefits of a bone mineral density test:

1. Early Bone Loss Detection: The BMD test allows you to detect if there is any bone loss before a fracture. This allows doctors to start treatment at the earliest stage.
2. Immediate Diagnosis: This test provides a detailed measurement of bone density, enabling doctors to easily diagnose osteoporosis or osteopenia.
3. Monitors Progress of Treatment: Doing BMD scans on a regular basis helps doctors in the easy evaluation of ongoing medications.
4. Measure Risk of Fracture: This test calculates the risk of your fracture in the future. Thus, doctors can take immediate action before any serious injury.
5. Painless and Non-invasive: The BMD test procedure needs no injections, needles, or any kind of discomfort.
6. Personalised Treatment: The BMD test reports enable doctors to design a targeted treatment depending on your bone health conditions.

Who Should Get the Bone Mineral Density Test?

Individuals with osteoporosis should get this test. It is mainly common among older women, but men can also have this. With age, the chances of osteoporosis increase.

This bone mineral density test is recommended for:

1. Woman aged 65 years or older
2. Postmenopausal woman aged 50 years or older
3. A woman at menopausal age with a high chance of breaking bones
4. Women who have passed the menopausal stage, or are younger with age less than 65 years, and have other risk factors for osteoporosis
5. Bone fracture after 50 years
6. Man aged 50 years or more with other risk factors
7. Losing more than 1.5 inches of your height
8. Experiencing back pain without any underlying cause
9. Women having irregular periods or have stopped, but are not pregnant or are not passing through the menopausal phase
10. Facing a significant drop in your hormonal level
11. Undergone an organ transplantation

Some particular types of prescription drugs cause bone loss. This includes glucocorticoids, a specific type of drug used to minimise inflammation.

What is the Bone Mineral Density Test Cost in India?

Note: The bone mineral density test cost mentioned above is approximate and may vary depending on the diagnostic centre and technology used. Make sure to check with your chosen diagnostic provider for the latest pricing.

Does Health Insurance Cover Bone Mineral Density Test?

Health insurance may cover the bone mineral density test if it is medically required and prescribed by a doctor. Here are some conditions:

1. Coverage Conditions: The majority of insurance plans offer coverage for the BMD test to individuals diagnosed with osteopenia, osteoporosis, and those at risk of fracture.
2. Age Relevant Coverage: Many insurers offer coverage for this BMD test, especially for women aged 65 years and older, while for men aged 70 years and older.
3. Referral of Doctor: It is mandatory to have a valid prescription or a referral from your prescribed doctor to obtain the reimbursement.
4. Government Schemes: In India, there are government health schemes like Ayushman Bharat offering coverage for this bone mineral density test for eligible individuals.

Make sure to consult your insurance provider before scheduling a test to avoid unnecessary expenses.