PET Scan is a test for examining organs in the body. The procedure involves the use of a special camera and a radioactive chemical, called a tracer. This liquid, mostly made of a substance the body can metabolize, like glucose, is injected into a vein through an intravenous device, or IV, in your arm. As the tracer moves through your body, it gives off a small positive charge that is picked up by the special camera. The camera captures these emissions and a computer turns the recording into a picture that can be examined by your physician. In conjunction with other tests, like computed tomography (CT SCANS), or magnetic resonance imaging (MRI), the PET scan is a proven diagnotic tool for the evaluation of cancer, blood flow and the functionality of organs.
Prior to the Procedure
- A comprehensive physical exam and patient health history may be taken.
- Tell your doctor about any medicines and herbal remedies you take. You may need to stop taking some medicines or change your dose before this test.
- Tell your doctor if you have diabetes and/or take medications for diabetes. Your doctor will inform you if you need to adjust your dosage prior to taking your PET scan.
- Tell your doctor if you experience anxiety from being in enclosed spaces or suffer from panic attacks.
- Tell your doctor if you are pregnant or breast-feeding.
- Do not smoke 24 hours before the test.
- Do not drink caffeine or alcohol 24 hours before the test.
- Do not eat or drink for at least 6 hours before the test.
Day of the Procedure
Your PET scan will be performed by a radiologist or nuclear medicine specialist and a technologist. The test is done while you lie on a table that is connected to a large scanner, camera and a series of computer. An intravenous tube, or IV will be placed in your arm to administer the radioactive tracer. You may need to wait 30 to 60 minutes for the tracer to move through your body. During this time, you may need to avoid moving and talking. If the PET scan includes images of your heart, electrodes for an EKG/ECG will be placed on your body.
For PET scans of the brain, patients may be asked to read, name letters or tell a story, especially when speech, reasoning, or memory are being tested. You will be provided with earplugs and blindfold to wear for your comfort. The technician will step out of the room, but will remain in constant communication with you and monitor you through a window. As the PET scanner moves around you, it is important to lie very still.
During the test, you will be alone in the scanner room. The technologist will watch you through a window and you will be able talk to him or her through a two-way intercom at all times. Allot anywhere from 1 to 3 hours for the preparation and completion of the test. Following the test, you should drink plenty of fluids for the next 24 hours to help flush the tracer out of your body.
Although the test is not painful, you may experience some discomfort if you get cold as you lie on the table. The table is hard and it may be difficult to lie very still. Tell the technician if you start to feel sick, nauseous, get a stomach or headache.