What is a PET and PET/CT?
PET (Positron Emission Tomography) is a type of nuclear medicine imaging that is useful for diagnosing cancer, heart disease and other medical conditions and abnormalities. PET scanning uses small amounts of radioactivity to create an image of the body's structures. Because PET scanning measures glucose metabolism, tissue activity, oxygen use and blood flow can be visualized.
PET/CT offers latest-generation computer technology to provide ongoing comparison between the findings of PET and CT scanning. The information from the two different types of scans, which are performed simultaneously, is automatically cross compared then fused to produce an image that is more precise and more accurately reflects subtle differences in the body's tissues and structures.
How do I prepare for the exam?
Metal objects such as jewelry, eyeglasses and dentures may affect CT images so should be removed prior to the exam. You may also need to remove hearing aids and removable dental work.
What will the exam be like?
Before the scan, you will change into a hospital gown and the imaging RN will start an IV in your arm and inject a dose of special radioactive glucose solution. You may feel a cold sensation in your arm when the tracer solution is injected. Although rare, you could have an allergic reaction to the radiotracer material-if you feel lightheaded, short of breath, or any other unusual sensation, tell the nurse immediately. The glucose solution takes about 60 minutes to travel to the areas of the body that are most metabolically active so that these tissues "light up" for the PET scanner to see. After the IV injection, you will be asked to rest quietly with minimal movement and talking so that the tracer material concentrates in the tissues to be studied.
A PET scanner is a large machine with a round opening in the middle. After the technologist assists you onto the exam table, you will be slid into the machine while lying on your back. Although you will be completely surrounded by the PET scanner, the ends of the "tunnel" remain open.
During the scan you may hear buzzing while the scanner is creating the images. It is important that you remain as still as possible during the imaging procedure. You will be in constant view by the technologist who sits behind a leaded glass window. The room has an intercom system so that you can communicate with the technologist as needed. The scan takes about 30 minutes to complete.
After the exam
You may resume your normal activities, including driving.
The radioactive material decays naturally and will pass out of your body in urine and stool within a few hours or days. Drink plenty of fluids for about 24 hours after the exam to flush your system of the tracer material.
Nursing mothers should wait 24 hours after receiving tracer material before resuming breast feeding. It is suggested that nursing mothers pump and store breast milk before the scan.
How will I learn of the results?
Scan results are usually available in 3-4 days. Contact your physician who requested the scan to discuss the results.
- Tell your doctor, technologist, or nurse if you are pregnant, think you might be, or are breastfeeding.
- Tell your doctor, technologist, or nurse if you are allergic to iodine or have any other allergies.
- Bring a list of your current medications to your scan appointment.