Characteristic CT findings distinguishing 2019 novel coronavirus disease (COVID-19) from influenza pneumonia

• DOI: 10.1007/s00330-020-06880-z
• Publication Date: 2020-04-22T15:04:07Z
• Authors: Hao Wang; Ran Wei; Guihua Rao; Jie Zhu; Bin Song
• Keywords: Adult; Male; Pneumonia, Viral; Diagnosis, Differential; Betacoronavirus; Young Adult; 03 medical and health sciences; 0302 clinical medicine; Influenza, Human; Humans; Pandemics; Aged; Retrospective Studies; SARS-CoV-2; COVID-19; General Medicine; Middle Aged; 3. Good health; Pleural Effusion; Radiology Nuclear Medicine and imaging; Chest; Female; Coronavirus Infections; Tomography, X-Ray Computed

To investigate the different CT characteristics which may distinguish influenza from 2019 coronavirus disease (COVID-19).A total of 13 confirmed patients with COVID-19 were enrolled from January 16, 2020, to February 25, 2020. Furthermore, 92 CT scans of confirmed patients with influenza pneumonia, including 76 with influenza A and 16 with influenza B, scanned between January 1, 2019, to February 25, 2020, were retrospectively reviewed. Pulmonary lesion distributions, number, attenuation, lobe predomination, margin, contour, ground-glass opacity involvement pattern, bronchial wall thickening, air bronchogram, tree-in-bud sign, interlobular septal thickening, intralobular septal thickening, and pleural effusion were evaluated in COVID-19 and influenza pneumonia cohorts.Peripheral and non-specific distributions in COVID-19 showed a markedly higher frequency compared with the influenza group (p < 0.05). Most lesions in COVID-19 showed balanced lobe localization, while in influenza pneumonia they were predominantly located in the inferior lobe (p < 0.05). COVID-19 presented a clear lesion margin and a shrinking contour compared with influenza pneumonia (p < 0.05). COVID-19 had a patchy or combination of GGO and consolidation opacities, while a cluster-like pattern and bronchial wall thickening were more frequently seen in influenza pneumonia (p < 0.05). The lesion number and attenuation, air bronchogram, tree-in-bud sign, interlobular septal thickening, and intralobular septal thickening were not significantly different between the two groups (all p > 0.05).Though viral pneumonias generally show similar imaging features, there are some characteristic CT findings which may help differentiating COVID-19 from influenza pneumonia.• CT can play an early warning role in the diagnosis of COVID-19 in the case of no epidemic exposure. • CT could be used for the differential diagnosis of influenza and COVID-19 with satisfactory accuracy. • COVID-19 had a patchy or combination of GGO and consolidation opacities with peripheral distribution and balanced lobe predomination.