Nuclear imaging produces images by detecting radiation from different parts of the body after a radioactive tracer material is administered. The images are recorded on computer and on film. Different types of nuclear imaging tests have different preparation instructions.
Nuclear medicine imaging is a method of producing images by detecting radiation from different parts of the body after a radioactive tracer is given to the patient. The images are digitally generated on a computer and transferred to a nuclear medicine physician, who interprets the images to make a diagnosis.
Radioactive tracers used in nuclear medicine are, in most cases, injected into a vein. For some studies, they may be given by mouth. These tracers aren’t 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.
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Nuclear imaging is used primarily to diagnose or treat illnesses. Conditions diagnosed by nuclear medicine imaging include:
Nuclear medicine imaging can also be used to treat conditions or to evaluate how treatment is working. One example of this is radioimmunotherapy, which combines radiation and immunotherapy to deliver radiation precisely to a targeted area.
The main difference between nuclear medicine imaging and other radiologic tests is that nuclear medicine imaging evaluates how organs function, whereas other imaging methods assess anatomy (how the organs look).
The advantage of assessing the function of an organ is that it helps physicians make a diagnosis and plan treatments for the part of the body being evaluated.
Before the test
There are no general rules for preparing for the nuclear medicine test, since each type of test has its own 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 medicine test at the Cleveland Clinic Imaging Institute and you are not sure how to prepare for it, please call 216.444.2772 for precise instructions.
On the day of the test
During the test
You will lie on a padded examination table under a gamma camera. You will be positioned under the camera while it 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, but some studies require more than one hour and, in some cases, more than one visit.
A series of crystals inside the head of 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.
How long the test lasts depends on the type of test you’re having. In general, the scans themselves might last about 30 to 60 minutes, not including the time that it takes the tracer to be absorbed. In some cases, like bone sans, absorbing the tracer could take 2 to 3 hours.
Some nuclear medicine exams involve imaging over multiple days.
Some people might be alarmed when they hear the word ‘radioactive,’ but the tracers used aren’t medicines and don’t have side effects. In addition, the level of radiation in this kind of test tends to be very low.
There is a very small chance that you might be allergic to the tracer. You should always make sure that your healthcare provider knows of any type of allergy you have.
Nuclear medicine scans can provide important information that you can’t get from other types of testing. These scans can be used instead of exploratory surgery to improve diagnosis and treatment quality. Often, illnesses can be discovered in their earliest stages.
After the test
Generally, you can resume your usual activities and normal diet immediately.
A note from Cleveland Clinic
Nuclear medicine tests are often the least-invasive and best ways to diagnose diseases and to monitor treatments. These tests are safe and effective. Your healthcare provider will discuss your options with you. Make sure you ask questions about things that concern you.
Last reviewed by a Cleveland Clinic medical professional on 04/20/2021.
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