What is a Bone Scan? Purpose, Procedure & Results

A bone scan is a nuclear imaging test that helps doctors see how well your bones are working throughout your entire body. It uses a small amount of radioactive material to create detailed pictures of your skeleton, showing areas where your bones are rebuilding themselves or where problems might exist.

Think of it as a special camera that can peek inside your bones to check their health. Unlike regular X-rays that only show bone structure, a bone scan reveals bone activity and metabolism. This makes it incredibly useful for detecting issues that might not show up on other tests.

What is a bone scan?

A bone scan is a safe nuclear medicine test that tracks how your bones absorb a radioactive tracer. The tracer is a tiny amount of radioactive material that gets injected into your bloodstream and travels to your bones.

Your bones naturally absorb this tracer, and areas with increased bone activity will absorb more of it. A special camera then captures images of where the tracer has collected, creating a map of your bone health. The entire process is painless and the radiation exposure is minimal.

The test is also called bone scintigraphy or skeletal scintigraphy. It's different from other bone tests because it shows how your bones function rather than just how they look.

Why is a bone scan done?

Doctors recommend bone scans to investigate unexplained bone pain, detect cancer spread to bones, or monitor bone diseases. It's one of the most sensitive tests for finding problems throughout your entire skeleton at once.

Your doctor might suggest this test if you have persistent bone pain that doesn't have an obvious cause. It can reveal stress fractures, infections, or other issues that regular X-rays might miss. The test is particularly helpful because it examines your whole body in one session.

Here are the main reasons doctors order bone scans:

• Detecting cancer that has spread to bones (bone metastases)
• Finding hidden fractures, especially stress fractures
• Diagnosing bone infections (osteomyelitis)
• Monitoring arthritis progression
• Evaluating unexplained bone pain
• Checking for bone disorders like Paget's disease
• Assessing bone healing after surgery or injury

The test is especially valuable for cancer patients because it can detect bone involvement before symptoms appear. Early detection often leads to better treatment outcomes.

What is the procedure for a bone scan?

The bone scan procedure happens in two main phases spread over several hours. First, you'll receive an injection of the radioactive tracer, then you'll wait while it travels through your body to your bones.

The actual scanning part is comfortable and requires you to lie still on a table while a large camera moves around your body. The entire process typically takes 3-4 hours, but most of that time is waiting for the tracer to be absorbed.

Here's what happens during your bone scan:

1. You'll receive a small injection of radioactive tracer into a vein in your arm
2. You'll wait 2-3 hours for the tracer to travel through your bloodstream to your bones
3. You'll be asked to drink plenty of water during the waiting period
4. You'll empty your bladder just before the scan begins
5. You'll lie on a scanning table while the camera takes pictures
6. The scanning process takes 30-60 minutes
7. You may need to change positions during scanning for different views

The injection feels like any regular shot, and the scanning itself is completely painless. You'll need to stay very still during the actual imaging to get clear pictures.

How to prepare for your bone scan?

Preparing for a bone scan is straightforward and requires minimal changes to your routine. You can eat normally and take your regular medications unless your doctor specifically tells you otherwise.

The main preparation involves staying well-hydrated and removing metal objects before the scan. Your doctor will give you specific instructions based on your individual situation, but most people can maintain their normal activities.

Here's how to prepare for your bone scan:

• Continue eating and drinking normally before the test
• Take your regular medications unless told otherwise
• Wear comfortable, loose-fitting clothing
• Remove jewelry, watches, and metal objects
• Tell your doctor if you're pregnant or breastfeeding
• Inform your doctor about recent barium studies or nuclear medicine tests
• Plan for a 3-4 hour appointment

If you're claustrophobic, let your doctor know beforehand. The scanning equipment is open, so most people feel comfortable, but your medical team can help if you have concerns.

How to read your bone scan results?

Bone scan results show areas of increased or decreased tracer uptake, which appear as "hot spots" or "cold spots" on the images. Hot spots indicate areas where your bones are more active, while cold spots suggest decreased bone activity.

A radiologist will interpret your scan and send a detailed report to your doctor. Normal results show even distribution of the tracer throughout your skeleton, while abnormal results reveal areas that need further investigation.

Understanding your bone scan results:

• Normal results: Even tracer distribution throughout your bones
• Hot spots: Areas with increased bone activity (may indicate healing, infection, or cancer)
• Cold spots: Areas with decreased bone activity (may suggest poor blood supply)
• Focal uptake: Concentrated tracer in specific areas
• Diffuse uptake: Widespread increased activity

Your doctor will explain what your specific results mean and whether you need additional tests. Remember that abnormal results don't automatically mean something serious – they simply indicate areas that need closer examination.

What is the best bone scan result?

The best bone scan result shows normal, even distribution of the radioactive tracer throughout your skeleton. This indicates that your bones are healthy and functioning properly without areas of excessive activity or damage.

A normal scan means your bones are absorbing the tracer at expected levels, suggesting good bone metabolism and blood flow. You won't see any obvious hot spots or cold spots that might indicate problems.

However, it's important to understand that bone scans are very sensitive tests. Sometimes they can detect normal processes like healing or age-related changes that aren't concerning but might appear as mild abnormalities.

What are the risk factors for abnormal bone scans?

Several factors can increase your likelihood of having an abnormal bone scan. Age is a significant factor, as older adults are more likely to have bone changes from wear and tear or underlying conditions.

Your medical history plays a crucial role in determining your risk. People with certain cancers, bone diseases, or previous injuries are more likely to have abnormal results.

Common risk factors for abnormal bone scans include:

• History of cancer, especially breast, prostate, lung, or kidney cancer
• Previous bone fractures or injuries
• Chronic bone or joint pain
• Age over 50 years
• Family history of bone diseases
• Certain medications that affect bone health
• Metabolic bone disorders
• Recent bone surgery or procedures

Having these risk factors doesn't mean you'll definitely have an abnormal scan, but your doctor will consider them when interpreting your results.

What are the possible complications of bone scans?

Bone scans are extremely safe procedures with very few complications. The amount of radiation you receive is small and comparable to other medical imaging tests like CT scans.

The radioactive tracer leaves your body naturally through your urine within a few days. Most people experience no side effects at all from the procedure.

Rare potential complications include:

• Allergic reaction to the tracer (extremely rare)
• Slight bruising or soreness at the injection site
• Very small risk from radiation exposure
• Discomfort from lying still during scanning

The radiation exposure from a bone scan is minimal and considered safe for most people. Your body eliminates the tracer quickly, and you won't be radioactive enough to affect others around you.

When should I see a doctor about bone scan results?

You should follow up with your doctor as scheduled to discuss your bone scan results, regardless of whether they're normal or abnormal. Your doctor will explain what the findings mean for your specific situation.

If your results show abnormalities, don't panic. Many abnormal findings require additional testing to determine their significance. Your doctor will guide you through next steps, which might include more detailed imaging or blood tests.

Contact your doctor promptly if you experience:

• Severe or worsening bone pain after the scan
• Signs of infection at the injection site
• Unusual symptoms that concern you
• Questions about your results or follow-up care

Remember that bone scans are diagnostic tools that help doctors make informed decisions about your care. Having the test done is a positive step toward understanding and maintaining your bone health.