Value Of High-Resolution Computed Tomography in the Differential Diagnosis of Imported COVID-19 and Seasonal Influenza Pneumonia:

Background: Nowadays, the world is facing COVID-19 pandemic, and seasonal influenza is also sweeping the world. Therefore, it is essential to make an early differential diagnosis between imported COVID-19 and seasonal influenza pneumonia. Objectives: The present study aimed to determine the diagnostic value of high-resolution computed tomography (HRCT) imaging characteristics for imported coronavirus disease 2019 (COVID-19) and seasonal influenza pneumonia. Methods: The HRCT imaging features with 22 cases of imported COVID-19 and 39 cases of seasonal influenza pneumonia were retrospectively analyzed in the current study. The patients with COVID-19 or influenza were diagnosed according to the World Health Organization guidelines and were confirmed following positive reverse transcription-polymerase chain reaction(RT-PCR) analysis of respiratory secretion samples.  Results: Both imported COVID-19 and influenza demonstrated multiple lesions. In the former, the lesions were mostly distributed in the subpleural of peripheral lung (90.9%), and some of them showed an anti-butterfly wing sign (18.2%; P<0.05). In the latter, the lesions were distributed around the bronchial vascular tree with subpleural lesions in peripheral lung (33.3%); nonetheless, they were fewer than those observed in the former (P<0.05). There were some differences in ground-glass opacity (GGO) (95.5% vs. 66.7%, respectively, P<0.05), consolidation (68.2% vs. 12.8%, respectively, P<0.05), and crazy paving sign (86.4% vs. 10.3%, respectively, P<0.05). The air bronchogram sign in the former appeared earlier than those in the latter. When both GGO lesions were mixed, the latter had more solid areas and higher density. Conclusions: The different chest HRCT features of COVID-19 and seasonal influenza pneumonia can provide considerable evidence for the early diagnosis of imported COVID-19 and seasonal influenza pneumonia and can be of great help for the prevention and control of COVID-19.