Overview of Influenza -- Etiology of Influenza -- Epidemiology of Influenza -- Pathomechanism of Influenza -- Complications of Influenza -- Radiological Modality -- Laboratory Test -- Influenza -- Type A H1N1 Influenza -- Human Infected H5N1 Avian Influenza -- Human Infected H7N9 Avian Influenza -- Human Infected H10N8 Avian Influenza.