A PET/CT - Positron emission tomography / computed tomography scan reveals information about both the structure and function of cells and tissues in the body during a single imaging session. During a PET/CT scan, the patient is first injected with a solution that contains a very small amount of radioactive material. The substance is absorbed by the particular organs or tissues being examined. By combining information about the body's anatomy and metabolic function, a PET/CT scan provides a more detailed picture of cancerous tissues than either test does alone. The images are captured in a single scan, which provides a high level of accuracy.