Fludeoxyglucose F18 (FDG) is a positron-emitting radiotracer used in conjunction with positron emission tomography (PET) for diagnosis and monitoring of various conditions. Standard imaging modalities such as X-ray, CT, and MRI allows the visualization of healthy and diseased tissue with great details. However, some diseases do not have any structural anatomic abnormalities, or they do not manifest until the late stage. Therefore, functional imaging techniques like PET scan can compliment structural modalities on overcoming some of the deficiencies. PET scan uses radiotracers that are injected into the patient before the scan to visualize the blood flow, metabolic, and biochemical activities in diseased and healthy tissues. FDG is a glucose analog, and it tends to accumulate in the tissue with high glucose demand like tumors and inflammatory cells.