CT findings of normal coronavirus disease 2019 patients during rehabilitation period

ABSTRACT

This study aimed to investigate the chest imaging finding of patients with coronavirus disease 2019 (COVID-19) in rehabilitation period. The clinical and imaging data of 80 patients with COVID-19 diagnosed as common type by the First People's Hospital of Xiaogan City, Hubei Province from 21 January 2020 to 23 February 2020 were collected. The discharge standard of the convalescent stage contained body temperature returned to normal over 3 days, significant improvement of respiratory tract symptoms and obviously absorbed inflammation as well as two negative consecutive respiratory tract pathogenic nucleic acid tests showed by the pulmonary imaging. HRCT manifestations of patients were dynamically observed and were compared with those at the time of admission. Typical syndrome and lesion distribution and morphology at convalescence stage were observed. HRCT of COVID-19 patients in convalescent period showed that the absorption of "fly swatter breaking sign" and "water inclusion sign" was decreased, with earlier and more obvious absorption of water inclusion sign. Compared with HRCT at the time of admission, localized patchy ground glass foci in the dorsolateral or posterior basal segments of both lungs, multi segmented ground glass density foci and diffusely distributed ground glass foci in the convalescent stage were obvious, the remaining interlobular interstitial and interlobular septal thickening, subpleural are shadow and irregular fibrous cord shadow foci among some patients were found and no obvious mediastinal lymphadenopathy and pleural effusion were found. The decrease of absorption of "broken fly swatter sign" and "wrapped water pipe sign" is a typical manifestation of the improvement of the general COVID-19 in the rehabilitation period. In the rehabilitation period, the discharged patients often left ground glass like changes, thickening of interlobular septum and/or interlobular septum, subpleural are shadow and residual interstitial inflammation. Only by popularizing HRCT in the clinical follow-up can effectively observe the dynamic changes of residual lesions, reduce the residual lesions and lower the risk of developing interstitial fibrosis.