With good reason, you probably think of radioactivity as something to avoid. But in a medical setting, radioactive material can tell you important things about your body.
There’s a medical test that uses a small amount of radioactive material to check the condition of your bones. It’s called a nuclear bone scan, and it’s also known as skeletal scintigraphy.
When you have the test, the radioactive material -- called a tracer or radionuclide -- will gather at places in your bones that are the site of chemical or physical changes. The radiation is then picked up by a scanner.
The picture made by the areas of radiation gives your doctor a kind of map of abnormal areas in your bones.
Why Do I Need This Test?
Nuclear scans are often used to find out whether cancer from another place in your body (such as your breast, for instance) has spread to your bones. You might hear a doctor or nurse called this metastatic cancer. Your doctor also might order the test if you have unexplained pain in your bones.
Bone scans can help diagnose several problems, including:
- Broken bones, especially hips, or stress fractures, which can be hard to see on X-rays
- Paget’s disease of the bone, which affects how new tissue replaces the old
- Cancer that started in the bone, rather than spreading from another place in your body
- Infection in your bone (called osteomyelitis) or in an artificial joint such as a hip or knee
- Dead bone tissue caused by poor blood supply (another name for this is avascular necrosis)
- Fibrous dysplasia, a genetic condition in which your body develops scarlike tissue instead of healthy bones
If you are concerned about the radiation, you should know it gives you about the same exposure as regular X-rays.
How Do I Get Ready?
You can eat and drink normally before your scan. You don’t really have to do anything special to prepare, but certain substances can interfere with the tracer. Tell your doctor if you’ve:
- Taken an over-the-counter medication containing bismuth (such as Pepto-Bismol)
- Recently had a test that used barium
It’s important to let your doctor know if there’s any chance you’re pregnant, because radiation can affect your baby. Alert the doctor, too, if you’re breastfeeding. You’ll need to follow precautions after the scan to avoid passing along radiation through your milk.
You’ll need to remove jewelry and other metal objects before the scan. You may have to change into a hospital gown.
How Does the Scan Work?
The first step in the procedure is the injection of the tracer material. A technician will do this through a vein in your arm or hand. You might feel a sting from the IV.
Then you wait for the tracer to travel through your body and bind to your bones. That can take 2 to 4 hours.
Your doctor might order a scan before your body absorbs the tracer for comparison, especially if you could have a bone infection. If you’re having two scans, the first will happen right after the injection.
While your body is absorbing the nuclear material, you’ll need to drink 4 to 6 glasses of water to flush extra tracer from your body. You’ll use the restroom before the test begins so any concentration in your urine doesn’t cause a misleading picture.
For the scan itself, you’ll lie on a table while the camera moves around you. You’ll have to remain very still for certain portions of the scan, and you may have to change positions several times. The scanning may take up to an hour. It’s not painful, but lying on the table may become uncomfortable.
The camera will pick up “hot spots” -- any place the nuclear material has gathered in your bones -- and “cold spots” where it did not.
What Happens After the Test?
There won’t be any restrictions on your activities, such as driving, after the scan. You’ll need to drink extra fluids for a few days to flush the remaining tracer out of your system. But don’t worry about exposing others to radiation -- you’re not dangerous.
You shouldn’t feel any side effects, but if you have pain or redness at the site of your IV, call your doctor.
The images from your scan will go first to a radiologist or physician who specializes in reading them. A report will be sent to your doctor, who will contact you with the results.