PET/CT Scans

What to Expect

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.

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 image set. It provides an image of metabolic function (PET) and an image of anatomy (CT) into a merged image of both the body’s metabolism and structure. PET/CT allows the early detection of cancer tumors enabling the radiologists to determine the stage of or extent of a disease. Evaluating the effectiveness of cancer therapy by tracking the progress of prescribed treatments and checking for cancer recurrence enables the physician to prescribe effective treatments.

How PET/CT Scan Works

Prior to the exam your glucose will be evaluated for appropriate levels. When appropriate you will then 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. It is important that you remain calm and inactive while the FDG absorbs. After this 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. It is important that you remain still 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 radiologists to review and interpret. A report will be sent to your referring physician.

PET/CT Scans Can Help Diagnose

Combined PET/CT scans are effective imaging scans to aid in the diagnosis of:

• Cancers
• Brain Disorders (Neurology) – PET/CT is used to evaluate various forms of dementia, such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. PET/CT can help pinpoint areas of the brain responsible for epileptic seizures to help evaluate, guide, and plan surgical treatment.
• Heart Disease

Exam Preparation

There is very little preparation needed for a PET/CT exam.

• Do not to eat six to eight hours prior to the exam but you may 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.
• Consult your physician prior to your PET/CT scan if you:
  • Are or may be pregnant.
  • Are diabetic.
  • Are unsure if you should take your medication.
  • Have had recent radiation therapy.

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, the interpreting radiologists will contact your referring physician to convey all pertinent information gathered from the scan. Please call your referring physician for scan results.