Nuclear Imaging

What is nuclear imaging?

Nuclear imaging is a method of producing images by detecting radiation from different parts of the body after a radioactive tracer material is given to the patient. The images are recorded on computer and on film. The nuclear imaging physician interprets the images to make a diagnosis.

Radioactive tracers used in nuclear medicine are, in most cases, injected into a vein. But for some studies they may be given by mouth. These tracers are not dyes or medicines, and they have no side effects. The amount of radiation a patient receives in a typical nuclear medicine scan tends to be very low.

How is nuclear imaging different than other radiologic tests?

The main difference between nuclear imaging and other radiologic tests is that nuclear imaging evaluates how organs function, whereas other imaging methods study anatomy, or how the organs look.

The advantage of measuring the function of an organ is that it helps physicians make a diagnosis and plan present or future treatments for the part of the body that is being evaluated.

Before the test

There are no general rules for preparing for the nuclear imaging test, since each type of nuclear imaging test has its own unique requirements.

For example, one test may require you to not eat or drink - except for water - from six hours before the test until the test is complete. Another test may have no restrictions at all.

If you are scheduled to have a nuclear imaging test at the Cleveland Clinic Imaging Institute and are not sure of how to prepare for it, please call 216.444.2772 for precise instructions.

On the day of the test

Please do not bring valuables such as jewelry or credit cards to the hospital.

You may be asked to change into a hospital gown.

The test is performed and the results are reviewed by registered and licensed technologists and interpreted by board-certified nuclear radiologists and physicians.

During the test

You will lie on a padded examination table under a gamma camera. You will be positioned under the camera for a variable amount of time while the camera takes a series of pictures. Because the pictures are taken at a constant rate, you will be asked to lie still.

The average imaging time is less than one hour. Some studies require more than one hour and, in some cases, more than one visit.

A computer connected to the camera detects the radiation coming from the body organ being examined, and forms a series of images. These images are interpreted by nuclear medicine physicians who search for any abnormalities or disease and then make a diagnosis.

After the test

Generally, you can resume your usual activities and normal diet immediately.



This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional health information, please contact the Center for Consumer Health Information at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771. If you prefer, you may visit or This document was last reviewed on: 2/7/2017