Initial CT features and dynamic evolution of early-stage patients with COVID-19

OBJECTIVE: To explore the initial CT features and dynamic evolution of early-stage patients with Coronavirus disease 2019 (COVID-19). METHODS: A total of 126 COVID-19 patients in the early stage were enrolled. The initial CT features and dynamic evolution characteristics of the progression and absorption process from the stage of admission to discharge were retrospectively analyzed in this study. RESULTS: The main initial CT features were as follows: bilateral distribution (112/126, 88.9%), diffuse distribution (106/126, 84.1%), multiple lesions (117/126, 92.9%), nodular shapes (84/126, 66.7%), patchy shapes (98/126, 77.8%), pure ground-glass opacities (GGO) (95/126, 75.4%), “vascular thickening sign” (98/126, 77.8%), “air bronchogram sign” (70/126, 55.6%), “crazy paving pattern” (93/126, 73.8%), and “pleura parallel sign” (72/126, 57.1%). The main dynamic evolution characteristics were as follows: ① Imaging findings of the progression process: the main CT changes were increased GGOs with consolidation (118/126, 93.7%), an increased “crazy paving pattern” (104/126, 82.5%), an increased “vascular thickening sign” (105/126, 83.3%), and an increased “air bronchogram sign” (95/126, 75.4%); ② Imaging findings of the absorption process: the main CT changes were the obvious absorption of consolidation displayed as inhomogeneous partial GGOs with fibrosis shadows, the occurrence of a “fishing net on trees sign” (45/126, 35.7%), an increased “fibrosis sign” (40/126, 31.7%), an increased “subpleural line sign” (35/126, 27.8%), a decreased “crazy paving pattern” (19.8%), and a decreased “vascular thickening sign” (23.8%); and ③ In the stage of discharge, the main CT manifestations were further absorption of GGOs, consolidation and fibrosis shadows in the lung, and no appearance of new lesions, with only a small amount of shadow with fibrotic streaks and reticulations remaining in some cases (16/126, 12.7%). CONCLUSION: The initial CT features and dynamic evolution of early-stage patients with COVID-19 have certain characteristics and regularity; CT of the chest is critical for early detection, evaluation of disease severity and follow-up of patients.