Nuclear Imaging

Nuclear imaging is a way that healthcare providers can get pictures of your insides by using a tiny label that highlights parts of your body (radioactive tracer). The labels in the tracer are so small — single atoms — that you can’t see them. But a special camera can take pictures or video of where it goes.

Nuclear imaging can show your provider how your organs work or where specific cells are in your body. It uses very low levels of radiation that leave your body within about a day when you pee.

Healthcare providers use nuclear imaging tests to get information about:

• How a specific organ, like your heart, thyroid or gallbladder, is working
• The flow of blood or other fluids around your body
• Where cancer cells are in your body

What does nuclear imaging diagnose?

Nuclear imaging can help diagnose cancer or issues with your:

• Blood
• Bones
• Brain
• Gallbladder
• Heart
• Kidneys
• Lungs
• Thyroid

What are common nuclear imaging tests?

PET scans and SPECT scans are some of the most common types of nuclear imaging. Other nuclear imaging tests include:

• Cisternogram scan
• HIDA scan
• Liver and spleen scan
• Lymphoscintigraphy
• Meckle’s scan
• MIBG scan
• MUGA scan
• Nuclear cardiac stress test
• Renal scan (kidney scan)
• Thyroid uptake and scan
• Whole-body bone scan

How do nuclear imaging tests work?

Nuclear imaging tests use radiotracers (radioactive tracers) to label parts of your body, like specific cells or fluids, that your provider wants to see. The radiotracer enters your body when:

• Your provider injects it with a needle.
• You swallow it in a pill.
• You breathe it in as a gas.

A camera may be able to detect the tracer immediately or you may need to wait several hours or a full day before getting imaging. Then, you’ll lie on a table while a special camera detects the radiation from the labels attached by the radiotracer. A nuclear medicine physician interprets the images and reports the results to your provider.

How do I prepare?

How you prepare for your nuclear imaging test depends on which test you’re getting. In general, you should wear comfortable clothing (a provider may ask you to change into a gown) and avoid wearing jewelry.

Each test has its own preparation requirements. For example, your provider may have you not eat or drink, except for water, for six hours before the test until the test is complete. For some scans, you have to swallow a pill several hours before the test. But some tests have no preparation requirements. Ask your provider if you have any questions about how to prepare for a specific test.

What should I expect during a nuclear imaging test?

While each test is a little different, the general steps of a nuclear imaging test include:

1. You swallow, breathe in or are injected with a radiotracer.
2. Immediately or within a day (depending on the test), a provider will take pictures of your body using a gamma camera.
3. A provider will position you on an exam table, under the camera.
4. For some tests, you’ll be hooked up to additional equipment that takes readings during the test, like electrodes on your chest.
5. The camera will take a series of pictures and send them to a monitor.
6. Your provider will interpret the images.
7. Your body will break down the radioactive materials. You’ll pee them out within a day.

How long does imaging take?

How long the test lasts depends on the type of test you’re having. In general, the scans themselves might take about 30 to 60 minutes. For some tests, you have to wait two to three hours or an entire day to let the tracer absorb. This means you might have to come back to the hospital or testing facility more than once to complete the test.

What should I expect after a nuclear imaging test?

After the test, you can usually go back to your usual activities and normal diet immediately. Sometimes, even low levels of radioactivity can show up on airport security scanners or other very sensitive radiation detectors. For this reason, your provider may give you a card for proof that you’ve had this test, in case you need to travel soon afterward. Scanners shouldn’t detect any radioactivity after 24 hours.

Are there risks or side effects of nuclear imaging tests?

Risks of nuclear imaging tests include:

• Allergic reaction to the tracer
• Harm to a fetus if you’re pregnant
• Harm to your baby if you’re breastfeeding

The risk for allergic reaction is low. Let your provider know about any allergies and if you’re pregnant or breastfeeding.

When should I know the results of a nuclear imaging test?

It usually takes a few days to a week to get the results of nuclear imaging tests. Your provider will review your results and let you know what the next steps are.

When should I call my doctor?

Contact your healthcare provider if you have any questions about how to prepare for the test or what the results mean.