Figure 1.

Evolution of the pure ground-glass opacities (GGO) on chest CT of patients with COVID-19. A 58-year-old woman who had close contact with individuals in Wuhan presented with fever for 2 days. (A1–A4) The first non-contrast-enhanced chest CT reveals multipleground-glass opacities in the right upper, middle, and lower lobes (initial chest CT). (B1–B4) Follow-up chest CT 4 days after the first shows that both the scope and density of the lesions increase (stage I*). (C1–C4) Follow-up chest CT 8 days after the first shows that the scope of the lesions increases while the density decreases (stage II*). (D1–D4) Follow-up chest CT 13 days after the first shows that the scope of the lesions decreases slightly while the density increases (stage III*). *The stage does not represent the course of COVID-19 but the time interval between the two adjacent CT scans.