Characterization of Pulmonary Pathology in the Golden Syrian Hamster Model of COVID-19 Using Micro-Computed Tomography.

The Golden Syrian hamster is a well-characterized rodent model for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-associated pneumonia. We sought to characterize the pulmonary disease course during SARS-CoV-2 infection (strain USA-WA1/2020) in the hamster model using micro-computed tomography (micro-CT) and compare radiologic observations with histopathologic findings. We observed a range of radiologic abnormalities, including ground glass opacities (GGOs), consolidations, air bronchograms, and pneumomediastinum. The appearance, distribution, and progression of these abnormalities in hamsters were similar to those observed in the lungs of coronavirus disease 2019 (COVID-19) patients by clinical CT and chest X-rays, and correlated with clinical signs and weight loss during the course of disease. Histopathological analysis of infected hamsters revealed lung pathology characteristic of COVID-19 pneumonia, and we observed a strong association between CT and histopathologic scorings. We also analyzed accumulation of air in the thoracic cavity by both manual and automated threshold-based segmentation and found that automated analysis significantly decreases the time needed for data analysis. Data presented here demonstrate that micro-CT imaging can be a major tool in preclinical investigative studies using animal models by providing early and detailed assessment of disease severity and outcomes.