Positron Emission Tomography (PET) is a revolutionary form of nuclear medicine that can show how cancer or infectious diseases affect the functioning of the body. A PET scan can distinguish between benign and malignant disorders (or between alive and dead tissue), unlike other imaging technologies which merely confirm the presence of a mass. A PET scan can, in many cases, identify diseases earlier and more specifically than other imaging technologies. PET can also help monitor the treatment of cancer, giving oncologists an advanced tool in the evaluation of prescribed therapies. Combining this technology with traditional CT scanning places metabolic studies and anatomic imaging in one, cutting-edge diagnostic tool.