CT imaging features and image evolution characteristics of coronavirus disease 2019

To analyze the imaging features of coronavirus disease 2019 (COVID-19) in different periods, and summarize the characteristics with itsdevelopment.

We retrospectively analyzed the CT image data of COVID-19 patients diagnosed by nucleic acid test and CT examination in 57 patients in Zhuzhou Central Hospital and Zhuzhou First People's Hospital, and summarized the characteristics of CT imaging and the development of lesions.

Most of the cases were characterized by peripheral distribution of lesions. A total of 37 cases (64.91%) were purely peripherally distributed, 16 cases (28.07%) coexisted with peripheral and mid-internal distribution, and 4 cases (7.02%) had simple mid-inner band distribution. In peripherally distributed cases, the long axis of the lesion was mostly parallel to the pleura in 36 cases (63.16%). In the case of inner-middle zone distribution, the long axis of the lesion was mostly parallel and surrounded the bronchial vascular bundle, or distributed along the lung lobules (31.58%). All cases had ground-glass-density foci, 31 cases (54.38%) had fine grid shadows in the lesions, 46 cases (80.70%) had thick vascular shadows in the lesions, and 23 cases (40.35%) showed signs of bronchial inflation. Among the 10 cases of "wrinkling shape" lesions in the first CT examination, except for 1 case without reexamination, the remaining 9 cases had different degrees of absorption in the second CT examination. Among the 26 cases of "wrinkling shape" lesions in the second CT examination, except for 11 cases without reexamination, the other 15 patients had different degrees of absorption in the third CT examination.

The early CT manifestations of COVID-19 are mostly ground-glass-density foci distributed in the subpleural region, some of which are distributed near the bronchial blood vessel bundle and in the central area of the lobule. As the course of the disease progresses, there may be varying degrees of solid components in the lesion. When the lesions show a "wrinkling shape", it is often suggested that the lesions will evolve towards the direction of absorption. These characteristics are of great value in assisting clinical diagnosis and dynamically observing changes undersuch condition.