A PET/CT scan is a combination of two noninvasive imaging tests: positron emission tomography (PET) and computed tomography (CT).
At NYU Langone, our expert radiologists review and interpret PET/CT scans to diagnose illnesses, evaluate a patient’s response to treatment, and check for the recurrence of several medical conditions, including cancer.
When you have a PET/CT scan, radiolabeled glucose, a form of glucose labeled with radioactive material, is injected intravenously. Much like a car uses gas to run, the cells of the body need glucose to work effectively. The radiolabeled glucose resembles glucose enough to be taken up by cells, but not enough to be used by them. As a result, cells that need more “gas” accumulate more of the radiolabeled glucose.
The PET/CT scanner detects where there is a concentration of radiolabeled glucose in the body, and thus where disease may be.
Preparing for a PET/CT Scan
You must fast for six hours before a PET/CT scan, and you are only able to drink plain water. Even ingesting a small amount of sugar can make the results of the test inaccurate.
If you have type 1 or type 2 diabetes, you are given specific instructions from our nurses after you schedule your appointment.
In order to have a PET/CT scan with contrast, you must have a blood test to check your creatinine levels within six weeks of your scan.
Please bring any previous imaging studies and reports with you if they were performed at another institution. You also need your identification card, insurance card, scan prescription, and related forms.
During a PET/CT Scan
When you arrive for your appointment, you need to change into a gown if you are wearing any clothing with metal in it. A locker is provided for your clothes and personal items.
Please advise a nurse or technologist if there is a chance you may be pregnant.
Before the scan, a nurse interviews you to get a detailed medical history, and places an intravenous (IV) line. If oral contrast is prescribed, this is when you drink the first portion. You are escorted into a private room, where you receive an injection of radiolabeled glucose and then rest quietly for approximately 45 to 60 minutes.
A few minutes before you go onto the scanner, you drink the second portion of your oral contrast and use the restroom. If IV contrast is used during the CT portion of the study, it is injected while you are on the scanner.
Scan lasts approximately 20 to 30 minutes. During the scan, you are visible to and can communicate with the technologist, who is present in the adjacent control room at all times.
After a PET/CT Scan
At the end of the scan, you are escorted back to the patient area and your IV is removed. You can change and have a snack. If necessary, additional instructions are given to you by the nurses.
The results of the scan are interpreted by our nuclear medicine physicians. The report is sent immediately to your referring physician, who contacts you with the results.
Questions or Comments about Your Visit
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Plan Your Visit
Perlmutter Cancer Center Radiology—34th Street
160 East 34th Street
2nd and 3rd Floors
New York, NY 10016
NYU Langone Radiology—NRAD, Lake Success, Suite 101
6 Ohio Drive
Lake Success, NY 11042