PET SCAN DEFINED
HOW PET WORKS
SAFETY


PET SCAN DEFINED

Positron Emission Tomography, or PET, is a valuable, painless, diagnostic test that allows radiologists (doctors who specialize in the use of imaging for diagnosing medical conditions) a unique view of your body’s biological functions. Perhaps you previously have had an x-ray or MRI (Magnetic Resonance Imaging) or CT (Computerized Tomography) scan. These diagnostic tests look at your body’s structure and provide important information about your body’s anatomy. The PET scan is different in that it looks at your body’s metabolic activity and provides important information about your body’s tissue. PET scans can be done on the brain, various parts of the body, or the entire body.

Virtually all diseases alter the body’s biochemical processes. PET is able to discover these changes in their earliest stages, often before any symptoms appear, and is of significant value in detecting certain cancers, neurological conditions and cardiac diseases. By comparing normal and abnormal tissue, PET scanning provides your doctor with accurate information that could help determine the most effective treatment plan for you.


HOW PET WORKS

Glucose is the most important carbohydrate formed by the body during digestion and is used to help nourish the body’s cells. Scientists know that normal and abnormal cells absorb glucose differently. PET allows radiologists to view this absorption to determine the health of the cells. This observation is made possible by injecting patients with a safe, low dose of short-lived positron-emitting isotopes in a glucose compound (FDG or F-18 fluorodeoxyglucose). In simplest terms, as FDG disperses throughout the body, it emits positrons (positively charged electrons) that are imaged by the PET scanner. A computer measures these signals and provides images and data on blood flow and metabolic processes within the tissues being observed. The manner in which the cells absorb FDG and emit positrons permits a radiologist to determine not only the presence of a disease, but also its stage and extent.


SAFETY

The PET exam is safe for patients of any age. However, if you are pregnant, or think you might be, you should tell the technologist before your scan.