Imaging Features of Early COVID-19 on Chest Thin-slice Non-Enhanced CT

Objective: To explore the characteristics findings of early COVID-19 on chest thin-slice non-enhanced CT. Materials and methods: From November to December 2022, data from 153 patients with COVID-19 with positive chest CT findings confirmed by the Department of Infectious Diseases of our hospital were collected. All patients had relatively complete clinical data and underwent chest CT 1-14 days after the onset. The patients were divided into two groups according to their age (≤60 years old and >60 years old) and the time interval between the onset and CT examination (≤7 days old and >7 days old), and the differences in CT features between the two groups were compared. Result: Among 153 patients with COVID-19, the lung (100%), blood vessels (93.5%), airways (73.4%), and pleura (70.1%) were involved. The comparison between the age groups showed statistically significant differences in the number, location, size, volume, and band shadow of the lesions. There were statistically significant differences in the shape, density, organization, fibrosis, and pleural involvement of the lesions between the patients in the time interval between the onset and CT examination. Conclusion: Chest thin-slice CT can clarify the location and scope of early COVID-19. Some characteristics findings can help for accurate diagnosis and differentiation, such as the diversity of morphology, intrapleural and perivascular distribution, interstitial lesions with alveoli as a unit, early mixed ground-glass shadow often accompanied by obvious organization and fibrosis, localized thickening of the pleura, and few pleural effusions.