This book presents the theory of influenza and its imaging characteristics. The first section introduces readers to the fundamental theory of influenza, including the etiology, epidemiology and pathogenesis of influenza, influenza-related diseases, and imaging technologies. The second section is divided into 5 chapters and includes extensive DR, CT and MRI images on H1N1 influenza, H5N1, H7N9, H5N6 and H10N8 avian influenza.?