Female Fitch ferrets were divided into five groups, with two per group of animals that were mock-infected with PBS (group 1) or intranasally infected with KY/180 (groups 2-5), in a 0.5 ml dose of 0.5610 6.0 TCID 50 per naris, on day 0 (Table 1) . Group 5 was the only group that was imaged each day; while groups 2-4 were imaged and sacrificed on days 1, 2 and 3 post-infection. This study design permitted evaluation of the progression of imaging with infection and pathology in two animals each day as well as continuous imaging of the lungs in one cohort over the seven-day time-period.