Dynamic Changes in Chest CT Images Over 167 Days in 11 Patients with COVID-19: A Case Series and Literature Review

Background: Recently, CT findings have been widely reported to be associated with the clinical severity of COVID-19. However, few studies have reported the correlation between CT findings and long-term outcomes in patients with COVID-19. Case presentation: Herein, we conducted a 167 day long-term follow-up of CT examination on 11 patients with COVID-19 to evaluate their long-term prognosis, particularly in severe cases. We found that the course of COVID-19 can be divided into four stages according to the characteristics of CT images: 1) early stage (1–4 days), with chest CT showing quasi-circular ground-glass shadows and fine mesh shadows; 2) progressive stage (5–10 days), showing lesion spread through the axial interstitium along the bronchi and gradual diffusion to the whole lung; 3) recovery stage (11–74 days), showing gradual absorption of the fibre cord, ground-glass, and consolidation shadows; and 4) normal stage (74 days later), indicating no serious permanent lung injuries. Conclusions: Our data indicate that chest CT can enable early detection of COVID-19 and determination of the different stages of COVID-19. Furthermore, mild cases tended to have better prognosis, whereas severe cases still showed cord-like fibrosis in the lungs in follow-up at the 167th day after symptom onset.