Nuclear medicine (NM) exams image body function rather than anatomy. This is done with the use of small amounts of radioactive materials, also know as radiopharmaceuticals or tracers, each of which is designed for uptake by specific organs or types of body tissue. The tracers are injected into a vein in the arm, inhaled or swallowed. A special camera, called a gamma camera, is used that maps the distribution of the radioactive tracer to create images which are studied by radiologists. Nuclear medicine exams are among the safest available in diagnostic imaging. An estimated 10 to 12 million nuclear medicine exams are performed annually in the United States. Only small amounts of radioactive tracer are used. The tracer loses most of its radioactivity in hours or days and is quickly eliminated from the body.
What does the equipment look like?
Reasons for Having a NM Scan
Nuclear medicine images can assist the physician in diagnosing diseases. Tumors, infection and other disorders can be detected by evaluating organ function. Specifically, nuclear medicine can be used to:
- Analyze kidney function
- Image blood flow and function of the heart
- Scan lungs for respiratory and blood-flow problems
- Identify blockage of the gallbladder
- Evaluate bones for fracture, infection, arthritis or tumor
- Determine the presence or spread of cancer
- Identify bleeding into the bowel
- Locate the presence of infection
- Measure thyroid activity to detect organ dysfunction
How do I prepare for a NM exam?
Please leave your jewelry and valuables at home. Please wear comfortable clothing with no metal or zippers to the exam. You may be asked to change clothes prior to the exam if necessary. Usually, no special preparation is needed for a nuclear medicine examination. However, if the procedure involves evaluation of the stomach, you may have to skip a meal before the test. If the procedure involves evaluation of the kidneys, you may need to drink plenty of water before the test. You should avoid caffeine (coffee, tea, etc.) and smoking for 48 hours before the examination. Continue taking medications with small amounts of water unless your physician says otherwise. Tell the technologist and supervising physician if you have asthma or a chronic lung disease or have problems with your knees, hips or keeping your balance, which may limit your ability to perform the exercise if needed for a specific procedure.
To prepare for a specific procedure please contact the Nuclear Medicine Department at:
What will I experience during and after the procedure?
The nuclear medicine technologist will explain the procedure, answer any questions you might have, and then give you a small amount of radioactive tracer, which is injected, swallowed, or inhaled. The imaging portion of your exam may begin immediately, or up to several hours later, depending on the kind of study you are having. If your exam is scheduled for later, you may leave the facility. Please find out when you should return and if you can eat and drink while you are gone. Some exams may require two visits to our facility.
When it is time for your images to be taken, the technologist will help position you on the exam table. A special camera will be positioned over the part of your body being studied to create a series of images. It is important to hold as still as possible while the images are being taken. The camera is open on both sides. For some exams the camera will be close to your face.
You may experience some minor discomfort from the intravenous injection of the radiopharmaceutical.
You will be asked to exercise until you are either too tired to continue or short of breath, or if you experience chest pain, leg pain, or other discomfort that causes you to want to stop.
If you are given a medication to increase blood flow because you are unable to exercise, the medication may induce a brief period of feeling anxious, dizzy, nauseous, shaky or short of breath. In rare instances, if the side effects of the medication are severe or make you too uncomfortable, other drugs can be given to stop the effects.
Most patients can resume regular activities immediately after the procedure. The radioactivity in your body will decrease due to the natural process of radioactive decay. In addition, radioactivity will decrease because the radiopharmaceutical passes out of the body in the urine or stool.
Who interprets the results and how do I get them?
A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you. In some cases the radiologist may discuss preliminary results with you at the conclusion of your examination.