Table 1.

Coronavirus disease 2019 infection staging based on chest computed tomography findings and number of days from the onset of the symptoms

Days (from onset of symptoms)	Stage	Typical findings
0-4	Early	GGO; Distribution: Unilateral/bilateral, lower lobes, peripheral
5-8	Progressive	GGO (diffuse); Crazy paving; Consolidation; Distribution: Bilateral, multilobar
9-13	Peak	Peak CT findings: day 10; GGO (diffuse); Crazy paving; Consolidation (dense); Parenchymal bands
≥ 14	Absorption	CT findings improve from day 14; Absorption of consolidation; GGO present; No crazy paving

GGO: Ground-glass opacities.