A positron emission tomography (PET) and computed tomography (CT) scan, or PET / CT scan, enables our doctors to see many of your organs to help diagnose a variety of diseases including:
- Breast cancer
- Colorectal cancer
- Esophageal cancer
- Head and neck cancer
- Lung cancer
- Thyroid cancer
- Heart disease
- Alzheimer’s disease
PET / CT scans enable us to see how your organs look and how they function. By fusing the CT and PET images, we can not only identify a tumor (PET) but also pinpoint its location (CT). And because the two tests are combined into one exam, you can receive both during a single convenient visit and using a single piece of equipment.
Find out what documents to bring
Preparing for a PET / CT scan
- Remove all metal, including jewelry, hair ornaments, watches, studs and coins.
- Do not eat or drink anything after midnight the night before your appointment.
- Remove all makeup prior to the exam.
- Avoid drinking coffee or large volumes of fluid prior to your scan.
- Avoid exercising for 24 hours before your scan.
- Tell your doctor if you feel uncomfortable or claustrophobic in a small space.
- You may be asked to wear a hospital gown during the exam or you may be allowed to wear your own clothing.
- You can continue to take regular medications.
- Patients with diabetes will receive special instructions to prepare for this exam.
For your safety
A PET / CT scan requires the injection of a small amount of a radiopharmaceutical into your bloodstream. There is no danger from this injection. The radiation exposure associated with PET / CT is similar to that of a conventional CT scan.
After you have received your injection, you will rest for about an hour to allow the injected material to be distributed through your body. You will then receive a CT exam followed by a PET scan on the same piece of equipment.
Tell your doctor or the technologist performing the exam if:
- You have allergies of any kind such as an allergy to iodine or X-ray contrast material, drugs, food, the environment or asthma.
- There is any possibility that you are pregnant and/or if you’re breastfeeding.
- You have serious health problems or have recently had surgery.
- You have any metallic implants.
- You are taking any medications including herbal supplements.
What to expect during a PET / CT scan
Although a PET / CT scan typically takes about 30 minutes, your entire visit can last up to two or three hours.
During the scan, you will be positioned upright on an exam table. If necessary, a nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm. Depending on the type of nuclear imaging exam you are undergoing, the dose of radiopharmaceutical is then injected intravenously, swallowed or inhaled as a gas.
It will take about one hour for the radiopharmaceutical to travel through your body and be absorbed by the organ or tissue being studied. You will be asked to rest quietly, avoiding movement and talking.
You will then be moved into the PET / CT scanner and the imaging will begin. You will need to remain still during imaging. The CT exam will be done first followed by the PET scan.
When the examination is complete, you may be asked to wait until the technologist verifies that they have all necessary images; then your IV will be removed.
A radiologist will review your exam images and report the findings to your doctor. Your doctor will then discuss the findings and next steps with you.