Fig. 5.

Distribution of ground-glass opacities in pulmonary edema and COVID-19 pneumonia. a, b Bilateral predominantly central GGOs are observed in a patient with pulmonary edema. Subpleural sparing is seen. There is also cardiomegaly and bilateral pleural effusion (asterisks). c, d In two different COVID-19 patients, diffuse GGOs are seen in bilateral upper lobes on axial CT images. The absence of ancillary findings such as pleural effusion and cardiomegaly may help in the differential diagnosis