Positron Emission Tomography (PET)
What is PET?
- Positron Emission Tomography (PET) is an advanced imaging technique that produces images of the body’s biological functions.
- Unlike X-rays, CTs (computed tomography), ultrasounds and MRIs (magnetic resonance imaging), PET does not show body structure (anatomy). Instead, it reveals the chemical function (metabolism) of an organ or tissue.
Why is it used?
- PET is used to diagnose and guide the treatment of a number of diseases including cancer, coronary heart disease, neurological disorders and seizure disorders.
- Specifically, PET is a valuable tool for the early detection and diagnosis of lung cancer, breast cancer, melanoma skin cancer, lymphoma, colon and rectal cancers, head and neck cancers, ovarian cancer, pancreatic cancer, and esophageal cancer.
- It is also used for staging and restaging.
- PET may reduce the need for further testing and diagnostic surgeries.
How is a PET scan planned and delivered?
- A PET scan is painless and can be performed in just a few hours as an outpatient procedure. The time required varies depending on what type of scan is being performed, but in most cases, a torso scan from eyes to mid-thigh takes about 2 hours. Some exams, such as brain or heart procedures, take as little as 60 minutes to complete.
- When a patient arrives for a PET scan, he or she will be registered by office personnel and taken
- to the PET area where a technologist will ask a series of medical history questions.
- A small blood sample is taken from the patient’s fingertip to check his or her blood-sugar or glucose level.
- The patient is then 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 be metabolized by the patient’s kidneys and excreted through the bladder.
- After injection, the patient relaxes and remains relatively still for about an hour.
- For the scan, the patient lies on a “scanning bed” that moves slowly through the PET scanner while the machine detects the injected tracer. When the imaging procedure is complete, the scanner sends the resulting information to a computer that generates several images which are reviewed by a specially-trained physician. A report and pictures detailing the findings are provided to the patient’s physician, usually within a day.