What is a PET/CT scan or a fusion scan?

A PET/CT scan combines PET and CT into one image. PET (Positron Emission Tomography) utilizes a low-level radiopharmaceutical or a “glucose tracer” to visualize processes within the body. The glucose tracer emits positrons, or positive electrons. As the positrons encounter electrons within the body, a reaction occurs which produces gamma rays. These gamma rays are then detected by the PET scanner. Therefore, the image produced by PET contains information about metabolic activity taking place in the body. Malignant or cancerous tumors are metabolically active so with that being said, PET is very good at determining whether or not a tumor is malignant through its metabolic activity.

CT stands for Computed Tomography. This technique uses x-rays to make cross-sectional images (called slices) of your body. The structure of body organs is more clearly visualized than with conventional x-rays. “Fusion” means that the anatomical information obtained from CT is combined with the biological PET information to form an image that records living tissues and life processes with great precision and detail.

Why is a PET/CT scan performed?
How does it help my doctor?

The PET/CT scan is a powerful tool used by doctors when evaluating patients who may or may not have cancer. It allows them to effectively diagnose and evaluate the cancer and whether or not it has spread to other areas of the body. It is often used to measure the shrinkage of a tumor, which ultimately guides a doctor’s therapy decisions. PET/CT is also used to direct or guide biopsies and surgeries as well as focusing radiation treatments. This scan essentially can be thought of as a tool that helps doctors see the whole picture because it gives them a better, more complete picture of his or her patient.

So how should I prepare for the test?

You should fast for at least 6 hours before your appointment time. You may drink water and should continue to take any prescribed medications. If you are diabetic, you should discuss your preparation with our staff.

How long does the test scan take?

After checking your blood sugar and receiving the glucose tracer, you will rest for 45-50 minutes. The total scan time will take less than 45 minutes. The entire process, will take between 1-1/2 and 2 hours.

What happens during the scan?

Following the 45 to 50 minute rest period, you will then be asked to lie down on the patient table. The scan rooms are typically cool, so you must dress warmly. You will be asked to hold your breath during the CT portion of the test. This will prevent chest movement which may blur the CT images. During the PET scan, just relax and lie as still as you can.

What if I’m pregnant?

Generally, neither the PET or CT scans are performed on pregnant women. If you are pregnant or you think you may be pregnant, contact your doctor immediately.

Will I be exposed to radiation?

You will be exposed to small amounts of radiation.
Your doctor ordered this test because the important information obtained from the scanning, far outweighs any potential risk from the small radiation exposure.

When can I resume normal activities?

You can resume normal activities right after the scanning is finished.

When will my doctor have my results?

A typed report will be faxed to your doctor’s office within 24 hours. The full signed report and fusion images are delivered within two days.

What if I have more questions about my upcoming scan or about PET Imaging at AMIC?

Please feel free to call us at 602.331.1771