74 Days Dynamic Changes of Chest CT Images of Coronavirus Disease 2019 (COVID-19) in Hebei Province, China

Liang, jianqin Liu Guizeng Yu Shuzhuang Yang Yang Li Yanchun Tian Hongli Chen Zhe

Background: Since December 2019, the COVID-19 infection broke out in many parts of the world with confirmed and death cases rapidly increasing, which posed a great threat to human life and health. Current nucleic acid detection and antibody testing for the SARS-CoV-2 were the main methods for diagnosis of COVID-19, but not so sensitive, with high false negative rate and missed diagnosis rate. Imaging changes of COVID-19 not only precede symptomatic changes, but also have different imaging characteristics in different periods. We conducted 74 days of dynamic chest CT imaging observation on COVID-19 patients in Hebei province, aiming to understand the dynamic characteristics of the chest CT changes of COVID-19, so as to find the source of infection early, take early intervention measures, and judge the prognosis. Methods: Chest CT examinations at intervals 1 to 4 days were conducted for 11 patients with a diagnosis of COVID-19. On the 74th day after onset, chest CT was reexamined to analyze the characteristics of chest CT in each stage. Results: Of the 11 cases, 1 case was imported from Wuhan, 10 cases were infected for family clustering after close contact with confirmed COVID-19 cases. There were 3 ordinary cases, 3 severe cases and 5 critical cases. Among them, 2 critical cases died for old age and complications of underlying diseases, while 9 cases were cured by April 7, 2020. The changes of chest CT imaging in 1 child appeared prior to the clinical symptoms. 1–4 days after onset of the initial symptom were the early stages: Chest CT was mainly characterized by single lung quasi-circular ground glass shadow and fine mesh shadow. 5–10 days were the progressive stages: The lesion spread along the axial interstitium of the bronchi and gradually diffused to the whole lung, and reach the peak on day 6 to 9, which was characterized by consolidation, paving stone sign, halo sign, reversed halo sign, and even ‘white lung’ for the critical patients. The recovery stages began on day 11 after onset: The fiber cord, ground glass and consolidation shadow were gradually absorbed. After 74 days of follow-up, no serious permanent lung injury was found. Conclusion: Chest CT could determine the different stages of COVID-19. Dynamic follow-up chest CT showed a good prognosis of COVID-19 in Hebei Province, China