PET/CT Services
What is Positron Emission Tomography – Computed Tomography (PET/CT) Scanning?
PET/CT Clinic Opens
Main Hospital
2nd Floor H2200
Positron emission tomography, also called PET imaging or a PET scan, is a type of nuclear medicine imaging.
Nuclear medicine is a branch of medical imaging that uses small amounts of radioactive material to diagnose or treat a variety of diseases, including many types of cancers, heart disease and certain other abnormalities within the body.
Nuclear medicine or radionuclide imaging procedures are noninvasive and usually painless medical tests that help physicians diagnose medical conditions. These imaging scans use radioactive materials called radiopharmaceuticals or radiotracers.
In some centers, nuclear medicine images can be superimposed with computed tomography (CT) or magnetic resonance imaging (MRI) to produce special views, a practice known as image fusion or co-registration. These views allow the information from two different studies to be correlated and interpreted on one image, leading to more precise information and accurate diagnoses. In addition, manufacturers are now making PET/CT units that are able to perform both imaging studies at the same time.
A PET scan measures important body functions, such as blood flow, oxygen use, and sugar (glucose) metabolism, to help doctors evaluate how well organs and tissues are functioning.
CT imaging uses special x-ray equipment, and in some cases a contrast material, to produce multiple images or pictures of the inside of the body. These images can then be interpreted by a radiologist on a computer monitor as printed images. CT imaging provides excellent anatomic information.
Today, most PET scans are performed on instruments that are combined PET and CT scanners. The combined PET/CT scans provide images that pinpoint the location of abnormal metabolic activity within the body. The combined scans have been shown to provide more accurate diagnoses than the two scans performed separately.
For more information, visit:
- RadiologyInfo - How Should I Prepare?
"The radiology information resource for patients" - Stanford Advance Medicine Center PET/CT
Preparing for PET/CT
Before your Appointment
Prepare a list, which includes:
- Names of medications you are currently taking
- Brief medical history
- Treatments you have had (Chemotherapy, Radiation Therapy, Surgery)
- Do not eat for at least 8 hours prior: We recommend that you have nothing to eat for at least 8 hours prior to your test (except water and your usual medications).
- Drink water: You are encouraged to drink 3-4 glasses of water prior to arriving at Stanford.
- Do not take your diabetic medication the morning of the test. You may take all other medications as usual.
- Confirmation of Appointment: You will receive an appointment reminder call 3 days prior to your appointment to confirm or cancel your appointment. If you do not get this message, please call the Stanford Radiology Call Center at (650)723-6855.
On the Day of your Appointment
- You should plan to be at Stanford a total of 2-3 hours on exam day.
- Arrive at the registration desk located on the 2nd Floor H2200 of the Main Hospital.
- You will be greeted by the PET/CT staff and they will take a small blood sugar sample and place a small intravenous line (IV) for a simple injection of the radioactive tracer called FDG. Both the blood test and the injection are necessary components of this study.
- Following the injection, you will be asked to sit quietly for 45-60 minutes.
- You will then be imaged on the PET/CT scanner for approximately 30-40 minutes.
During the Scan
You will be required to lie flat with your arms raised above your head. If you think you will be unable to keep your arms above your head for approximately 35 minutes, please notify the technologist and they may accommodate you.
Frequently Asked Questions (FAQs)
- Are there any side effects?
You will feel no side effects from the radioactive injection. - What do I do after the test is finished?
You may go home when the study is finished and resume your regular diet and medication. You are encouraged to drink water to help clear the radioactivity from your body. - How do I find out about my test results?
Test results will be forwarded to your physician within 2 days. - Can I have a PET/CT scan if I am allergic to contrast dyes?
Yes - Can I take my medication the morning of the test?
Yes, unless it is for diabetes. All diabetic medication should be brought with you to the scanner. Please also bring your home glucometer. - What are proteins?
Meat, milk products, cheese, nuts etc.
Atkin's diet is an appropriate diet to have the day before a scan. - What are carbohydrates?
Bread, potatoes, pasta, beans, rice, sugar, sweets. - Can I continue to have liquid protein tube feeds?
Yes the day before, however, we would like them to be stopped at midnight. - Can I exercise the day before?
Only routine light exercise. - Can I have sex the night before?
Yes, as long as you would not classify it strenuous exercise. - Can I drink alcohol the night before?
It is best not to have alcohol. - Can I have caffeine?
It is best to only have water on the day of the test. - How long is the test?
2 - 3 hours. - Why does it take so long?
We must wait 60 minutes after the injection of the isotope before we can start the scan. The scan itself only takes 40 minutes. - Can I wear body jewelry?
It would be best to come without any body jewelry. - How is a PET/CT scan different from a CT scan?
The PET let€™s us look at glucose or sugar uptake by the cells of your body. The CT scan lets us get a clear image of the organs and tissues. Therefore, the PET scan defines sugar utilization of the tissues and a CT scan defines location and size, i.e. anatomy.
View all Imaging Services