Fig. 4From: Nomogram to identify severe coronavirus disease 2019 (COVID-19) based on initial clinical and CT characteristics: a multi-center studyChest CT images of a patient with severe COVID-19. a-b Axial CT images showed bilateral multifocal ground-glass opacity (GGO) in multiple lung segments. Mosaic perfusion sign composed of GGO (red arrow) and transparent shadow (black arrowhead) was present in the bilateral lower lobeBack to article page