Positron Emission Tomography/Computed Tomography (PET/CT)

Positron Emission Tomography (PET) exposes the body’s physiologic changes, revealing both normal and abnormal tissue activity (tumors), while Computed Tomography (CT) reveals the detailed structure of the anatomy where the activity is taking place. This integrated information enhances the physician’s ability to detect and localize cancer at earlier stages, as well as to better define the stage of the tumor. Currently, integrated PET and CT scans are being used for breast, esophageal, cervical, melanoma, lymphoma, lung, colorectal, head & neck and ovarian cancers.

What are PET and CT Scans?

• A PET/CT scanner combines Positron Emission Tomography (PET) and Computed Tomography (CT) to create highly advanced medical imaging technique.
• The PET/CT scanner registers and fuses the anatomical image from the CT with the image of the metabolic activity from the PET during a single exam.
• PET and CT scans show the body’s physiologic changes, revealing tumors and tissue activity that are not captured by other diagnostic technologies, while simultaneously revealing the structure of the anatomy where the activity is taking place.  

 Why is it used?

• Integrated information combined PET and CT scans can be used in the detection and localization of a variety of cancers, including breast, esophageal, melanoma, lymphoma, lung, colorectal, head & neck and ovarian cancers.
• When information from PET and CT scans is integrated, it can be used with increased diagnostic confidence and provides better definition of the stage of the tumor.
• The combined PET and CT images enhance the physician’s ability to diagnose cancer at earlier stages, including recurrent cancers.
• It provides clearer assessment of response to treatments, such as chemotherapy or radiation therapy.
• A PET/CT scan may reduce the need for invasive procedures, such as biopsies and surgeries.
• Because a PET/CT scan combines two commonly used imaging techniques into one session, it may reduce the number of tests a patient would need to undergo.

 How is a PET/CT scan performed?

• A PET/CT scan can be performed in less than two hours as an outpatient procedure. The time required varies depending on what type of scan is being performed; in most cases, a scan from eyes to mid thigh takes about 90 minutes. Some exams, such as brain or heart procedures, take as little as 60 minutes to complete.
• When a patient arrives for a scan, he or she will be registered by office personnel and taken to the imaging area where a technologist will ask a series of medical history questions.
• The technologist will give the patient a fruit-flavored drink that will show up on the CT scan. This “contrast” solution helps the radiologist to clearly see the patient's stomach and intestines on the CT images so he may distinguish them from other structures in the abdomen. This solution is harmless and will eventually be excreted by the kidneys and bladder.
• A small blood sample will be taken from the patient’s fingertip to check the blood-sugar (glucose) level.
• The patient is injected with a small amount of radioactive glucose through an intravenous (IV) line. This substance is called a “tracer” and will be distributed throughout the patient’s body. It is safe, effective and has no side effects. It will eventually be excreted by the kidneys and bladder.
• After the injection, the patient should remain relatively still for about an hour.
• For the scan, the patient will lie on a “scanning bed” that moves slowly through the PET/CT scanner while the machine scans the body. During the first minute or so, the patient will be asked to perform slow, shallow breathing while the bed moves through the scanner twice to perform the CT scan. The rest of the time (25-30 minutes), the patient will move in steps lasting 5 minutes through the PET scanner while it detects the injected tracer. It’s very important that the patient does not move or adjust position during this 30 minutes so the two scans will be perfectly aligned. When the imaging procedure is complete, the scanner will send the resulting information to a computer that displays the PET and CT images side by side. A radiologist will review the information and provide a report and picture detailing the findings to the physician, usually within a day.

Click here for a patient brochure about PET/CT.

CCC's PET/CT program operates under the name Carolinas Clinical PET Institute and is located at 200 Andrews Street, Suite 100 in Greenville, SC. To make a referral, please call 864-527-8500.