While a computed tomography (CT) scan presents a detailed image of tissues and organs inside the human body, a positron emission tomography (PET) scan detects and shows abnormal activity. By combining the two imaging techniques, one can get detailed cancer information, learn its stage, and chart the course of treatment. The hybrid device, pet CT has revolutionized the face of medical diagnosis by the amalgamation of functional information obtained by PET and structural details of CT scans to provide precise and localized results.