This issue of PET Clinics examines the Contribution of FDG to Modern Medicine. In the first of two issues, articles include: The Basic Principles of FDG-PET/CT Imaging; FDG-PET in Diffuse Large B-cell Lymphoma; FDG-PET in Thoracic Malignancies; FDG-PET/CT in Gastrointestinal Malignancies; FDG-PET/CT in Infectious and Inflammatory Diseases; FDG in Urologic Malignancies; FDG-PET for Interventional Oncology in Liver Malignancy; FDG-PET in Neurology and Psychiatry, and more!