PET / CT is a diagnostic tool used to create a combined image of the metabolic activity of the body’s tissues and their structures. The body’s tissues use glucose (sugar) molecules for energy. By labeling glucose with a radioactive tracer, Fluorine-18 (FDG), Nuclear Medicine scanners are able to identify abnormal glucose use in the body’s tissues. Metabolic abnormalities can indicate the presence of diseases like cancer, heart disease, or changes in the brain.
The radioactive tracer, FDG, is injected into the bloodstream which distributes it throughout the body’s tissues. The cells then contain small amounts of radioactivity, which the PET scanner is able to detect and generate into an image of the body’s tissue metabolism. This PET image is then analyzed for abnormalities that could indicate diseases. PET/CT combines this metabolic PET image with the anatomical image of a CT scan. This give physicians a very precise image of both the body’s tissue function and structure in order to provide more accurate diagnosis and treatment planning.