Abstract
ABSTRACT:
Objectives: To find features differentiating Covid -19 from Swine flu on HRCT
Methods: A total of 148 Covid -19 patients and 84 Swine flu patients were enrolled in the study with positive RT PCR. HRCT lung of these patients from January 2019 to May 2020 were retrospectively analyzed. Findings like ground-glass opacities, consolidation, distribution of lesions, vessel engorgement, reverse halo sign, centrilobular nodules, pleural effusion, and mediastinal lymphadenopathy were evaluated and compared.
Results: Ground glass opacities in a peripheral distribution, vessel engorgement, and architectural distortion were the predominant findings in Covid19 pneumonia and showed statistical difference(p<.00001). Although consolidation was a common finding in both Covid-19 and Swine flu, the distribution of these lesions was random in Swine flu. Centrilobular nodules, pleural effusion was a characteristic finding of H1N1 infection with the statistical difference(p<.00001). Reverse halo though was found only in Covid -19; it was not statistically significant(p>.01)

Conclusion: Covid-19 and Swine flu, the two viral types of pneumonia that caused pandemics, can be distinguished on HRCT lungs by the presence of lesions typical to each virus infection and the difference in the distribution pattern of the lesions common in both diseases.