COVID-19 pandemic in flu season. Chest computed tomography - what we know so far

Abstract

Chest computed tomography (CT) is proven to have high sensitivity in COVID-19 diagnosis. It is available in most emergency wards, and in contrast to polymerase chain reaction (PCR) it can be obtained in several minutes. However, its imaging features change during the course of the disease and overlap with other viral pneumonias, including influenza pneumonia. In this brief analysis we review the recent literature about chest CT features, useful radiological scales, and COVID-19 differentiation with other viral infections.

Keywords: COVID-19; chest CT; ground glass opacities; viral pneumonia.

Figure 1

Multifocal ground-glass opacities

Figure 2

Air space consolidation. The image shows also ground-glass opacities, crazy paving, bronchovascular thickening, and vascular dilatation

Figure 3

Crazy paving appearance. The image shows also bronchovascular thickening, vascular dilatation, traction bronchiectasis, subpleural bands and architectural distortion, and air space consolidation

Figure 4

Reversed halo sign

Figure 5

COVID 19: Bilateral ground-glass opacities, crazy paving appearance, vascular dilatation, subpleural bands and architectural distortion. The distribution of changes is bilateral and peripheral

Figure 6

Influenza A pneumonia: computed tomography – consolidation (arrows), diffuse ground-glass opacities, interlobular septal thickening (arrowheads). The distribution of changes is mainly in the lower lobes. The peripheral distribution of consolidation is not as strong as in COVID-19 pneumonia (image from Koo et al. [35])

Figure 7

DL-based CT Pneumonia Analysis Prototype (Siemens Healthinners, Erlangen, Germany)