PET/CT is an imaging tool that combines two scan techniques, Positron Emission Tomography (PET) and Computed Tomography (CT), into one set of images.
PET scans measure metabolic activity and molecular function by using a radioactive glucose injection. All cells use glucose as an energy source. However, cancer cells grow faster than normal healthy cells and they use glucose at a much higher rate than normal cells. This is the basis of imaging with a radioactive glucose injection for cancer detection in PET scan. The PET scanner detects the radiation emitted from the patient after the injection, and the computer generates three-dimensional images of cell activity in the tissues of the body. These images can detect disease earlier than the anatomic information gained from CT alone.