Preparing for PET/CT Scans
What is a PET/CT Scan?
PET is an acronym for Positron Emission
Tomography. PET is a test that uses special
imaging cameras and a radioactive type of
sugar to produce pictures of the function
and metabolism of the cells in the body.
CT stands for Computerized Tomography. CT is an x-ray test that generates a detailed view of the anatomy or structure of organs and tissues in the body. The CT scan can show the dimension of vessels, lymph nodes and organ systems.
A PET/CT scan merges both technologies into a single machine. It provides a picture of function (PET), a picture of anatomy (CT) and a merged picture of both the body’s metabolism and structure.
Exam Preparation
There is very little preparation needed for a
PET/CT exam. Typically you will be asked not
to eat 6-8 hours prior to the exam but you can
drink water. If you’re taking medication please
consult with your physician before the exam.
Most medications can be taken the day of the
exam. Please avoid strenuous exercise 24 hours
before your appointment.
You may be asked to put on a gown for the exam so dress comfortably and expect to change your clothes.
Please do not wear any jewelry.
The Exam
Prior to the exam you will receive a small
injection of radioactive sugar (FDG). You will be
asked to sit or lay down on a comfortable chair
or bed for 30-60 minutes while the FDG travels
throughout your body.
After this short time, the technologist will assist you to the scanner. The CT portion of the exam is completed first followed by the PET portion. You may be asked to hold your breath for several seconds while the CT scan is performed. The technologist will tell you if this is needed.
It is important that you don’t move for the duration of the scan. The length of the exam is determined by your height and area of interest. Most PET/CT scans are typically completed within 20-40 minutes.
When the total scan is finished, the computers will produce images for the doctor to review.
After
Once the total scan has been performed you
may resume normal daily activity. Even though
the FDG will quickly leave your body, you can
expedite the process by drinking plenty of water
after your scan is complete.
Your PET/CT results will not be immediately available, but the reading physician will contact your referring physician to convey all pertinent information gathered from the scan. Please call your referring physician for scan results.
Consult your physician prior to your PET/CT scan if…
- You are or may be pregnant,
- You are diabetic,
- You are unsure if you should take your medication, or
- You have had recent radiation therapy.


