PET CT Scan

This examination combines two scanning techniques into one — the PET (positron emission tomography), which shows different functions in the body, and the CT (computed tomography), which shows the detailed structural anatomy. This combination allows doctors to get highly defined 3D images from the inside of the body with only one system and during one appointment. It combines both functional and anatomical information into one single scan. Your doctor will be able to pinpoint the exact location of interest and determine its functional status. One of the most important factors in the fight against any disease is early detection. A PET/CT scan provides your doctor with information that may help to specify and improve any treatment that you require and possibly even reduce the risk of surgical procedures.

What can I expect from a PET CT procedure?

A PET/CT examination is straightforward and painless. You will receive a small injection of a harmless radiolabeled sugar called FDG. This will circulate through your body and will be metabolized or “used” by the cells and organs. Some cells and many diseases use this sugar more than others, and the PET system can measure these differences. For this reason, after the small injection, you will be asked to relax for about an hour while the sugar circulates. Afterward, you will be asked to lie down on the scanner bed. Simply relax and follow the technologist’s instructions. It is very important to remain as still as possible during the exam and breathe normally unless told otherwise. You may be required to keep your arms over your head during the exam.

The scanner bed will move in toward the scanner opening for a short time, during which you will hear some noise coming from the system. This will complete the CT portion of the scan. Next, the PET scan will begin. The bed will once again move, but not as quickly. The technologist will keep you informed about what is going on. Although tissues in the body will normally process FDG, diseased cells process the FDG more rapidly than healthy tissues. It is this increased absorption of FDG that is captured by the PET scan and determines if there are any problem areas. When the PET and CT images are combined, it completes the entire picture and helps your physician in making an accurate diagnosis.

How do I prepare for a PET CT scan?

Patients will be provided with detailed instructions on scans from their physicians. Some people, such as women who are pregnant or breastfeeding, should not receive a nuclear medicine scan. Patients should discuss any health issues that may rule out the use of nuclear scans with their physicians. Depending on the test being done, patients may be asked to avoid food and/or water for a period of time before the test. A change in diet or medications taken in the weeks before the test may be required.