A radionuclide is a chemical that is radioactive. Doctors give you a small dose of the radionuclide. The radionuclide gives off radiation that's picked up by a scanner placed over a certain area of your body. The scanner makes a picture of where the radiation is and how strong it is. This helps show doctors what's going on in the tissue they're testing.
Doctors can give you a radionuclide as:
Different radionuclides go to different parts of your body. Doctors pick which radionuclide to use depending on what they need a picture of. A radionuclide scan can help doctors find problems in many parts of your body:
Doctors usually use this test to find problems such as:
Sometimes, doctors will use the test to see how well a part of your body is working. For example, doctors may see how your heart works when it’s pumping hard by doing the test while you walk or run on a treadmill. If you’ve had a heart attack, doctors may do this test to see how well your heart is recovering.
You'll be exposed to much more radiation than a plain x-ray Plain X-Rays A plain x-ray is an imaging test that takes a picture of the inside of your body. It uses a low dose of x-ray radiation. X-rays show body parts according to how dense (solid) they are. Doctors... read more . Doctors try to limit the total amount of radiation you are exposed to over your lifetime. Getting too much radiation can raise your chance of getting cancer.
If you’re pregnant or could be pregnant, tell doctors before you get radionuclide scanning.
Radionuclides stay in your body for a few days. If you plan to fly on an airplane within a few days after getting this test, you may set off radioactivity alarms in the airport. Get a doctor’s note to have at the airport.
The test can take a long time, up to several hours
Radionuclide scans aren't as detailed as pictures from other imaging tests, such as x-rays Plain X-Rays A plain x-ray is an imaging test that takes a picture of the inside of your body. It uses a low dose of x-ray radiation. X-rays show body parts according to how dense (solid) they are. Doctors... read more , CT scans Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more , or MRIs Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more