Nuclear Imaging
What is nuclear imaging?
Nuclear imaging is a specialized procedure that uses small amounts of radioactive material, or tracer, to diagnose and treat a number of diseases. During a nuclear imaging test, the radioactive tracer, which is formulated to collect in specific organs, bones or tissues, is injected into the body. A specialized (gamma) camera is then used to detect the radiation throughout the body and provide information about the area in question.
Unlike X-rays and other conventional radiological procedures, nuclear imaging can determine the cause of a medical problem by showing the function of an organ, bone or tissue, rather than just its structural appearance. As a result, this procedure often identifies abnormalities very early in the progression of a disease - long before they are apparent in other diagnostic tests.
What should I expect?
How long will it take?
How do I prepare?
Locations
What will happen during my nuclear imaging exam?
Most nuclear imaging exams are done by injecting a small dose of radioactive tracer into a vein (usually at the elbow), though sometimes the tracer is administered orally. Depending on which type of scan is being done, the imaging will be carried out either immediately after the injection, a few hours later or several days later.
At the beginning of the procedure, an experienced nuclear technologist will position you on an examination table and then place the gamma camera close to the part of your body being examined. While the camera takes a series of pictures, you will be required to remain as still as possible. The scan is painless, and you will be able to communicate with the technologist at any time during the procedure.
The amount of radioactive material used in the procedure is extremely small, so radiation exposure is minimal. Moreover, the images and information provided by nuclear medicine exams cannot be attained by other imaging procedures. The benefit of accurate diagnostic information far outweighs the minimal risk of introducing a minute quantity of radiation into the body.
How long will the nuclear imaging procedure take?
The length of the procedure varies with each type of exam. The time between the administering of the tracer and the taking of the images may range from a few minutes to a few days, depending on the body part being examined and the tracer being used. Different tracers require different amounts of time to accumulate in certain parts of the body.
The time required to obtain the images also varies. Some tests will take 20 minutes, while others may take several hours. Longer imaging exams may be broken down into several sessions and carried out over a number of days. Once all the necessary images are collected and processed, a radiologist with specialized training in nuclear medicine will interpret them and forward a report to your physician.
Allergies, side effects and other reactions are extremely rare, as very small doses of tracer are used. However, you should inform the technologist if you have a history of allergies, or if you are currently taking any medication. And, as with all radiological procedures, be sure to inform the technologist if you are pregnant or nursing.
How should I prepare for my nuclear imaging exam?
Some nuclear imaging tests require no special preparation, while others have unique requirements. Below is a list of nuclear scans that require some preparation prior to the exam:
Thyroid Scan
- Discontinue thyroid medication for 2 weeks prior to exam.
- No X-ray or CT intravenous dye for 4 weeks prior to exam.
Biliary (HIDA) Scan
Avoid having anything to eat or drink for 12 hours prior to your exam.
Gastric Emptying Scan
Avoid having anything to eat or drink for 6 hours prior to your exam.
Myocardial Imaging
Avoid having anything to eat or drink for 6 hours prior to your exam.
