PET? What is it? When is it useful?

PET is a robust diagnostic test, based on the principle of biological imaging. Standard diagnostic scans such as CT and MRI scans show details about the structure of the body. However, since diseases such as a cancer are biological processes, PET scans can more accurately detect and stage most cancers. Another advantage of PET is that a single examination can evaluate the entire body, detecting abnormalities that may not have been found on other imaging modalities.

PET can also be of significant value in the seizure disorders of the brain. Research is underway to evaluate its utility in the early diagnosis of Alzheimer’s disease. PET is found to be useful in selecting patients with coronary artery disease who might benefit from coronary angioplasty or coronary artery bypass surgery.

What is the basis of PET?

The reason why cancer is so deadly is because cancer cells grow much more rapidly compared to normal body tissues. They do so by means of a very proficient cellular system, which metabolizes nutrients such as glucose at a much faster rate. Since PET uses a tracer drug chemically attached to glucose or other compounds, cancer sites in the body accumulate these compounds in a higher amount, resulting in hot spots that are easily detected by PET.

How can I arrange for a PET scan at the Columbus Circle Imaging?

To arrange a PET Scan, or to obtain further information, please call Loretta McDonald at (212) 977-4100.

If you had other imaging studies performed such as X-rays, CT scans, MRI, ultrasound etc, it is very crucial that the films and reports are made available to the radiologist who is interpreting the PET scan. If these studies were performed at Columbus Circle Imaging or one of the West Side Radiology facilities or at St Luke’s-Roosevelt Hospital Center, they will be made available to the radiologist interpreting the PET scan. If they were performed at other facilities, you should bring the films and reports along

with you when you come for the scan. These films and reports will be returned to you at the completion of the scan or at a later time.

How long does it take to complete a PET scan?

Approximately two hours. First you will receive intravenous injection of tracer drug with glucose (F-18 FDG) in your arm. The drug will be allowed to distribute in your body for approximately one hour, while you are relaxing. Then you will be placed in a scanner table and PET imaging will be performed, lasting for about one hour.

Later on, the technologist will process the scan and the results will be made available for the radiologist to read. The radiologist will in turn review the scan, call your physician and generate a report.

What types of preparations are necessary for a PET Scan?

Fasting for a minimum of six hours is absolutely essential. If you are scheduled to have a PET scan early in the morning, you can have your regular meal the night before the scan. Intake of water does not interfere with the scan. You can continue to take your prescribed medications and should drink generous amount of water before and after the scan.

If you are diabetic, you should take small, regular meals to keep glucose under control and continue to take your oral glucose medications or insulin. Please arrange the timing of the scan such that it is performed at least 4 hours after your last insulin injection. A blood sugar check will be performed before you receive the injection of the F-18 FDG, a PET tracer containing a glucose compound. The blood glucose should be less than 200 mg/dl. The amount of glucose in the injection is very small and therefore it does not interfere with your blood glucose levels.