Table I.

Lung parenchyma lesions on chest computed tomography (CT) (Recommendation of the French Society of Thoracic Imaging)

Chest CT severity	Extent of lesions % of lung parenchyma
Stage 1: minimal	<10
Stage 2: moderate	10-25
Stage 3: extended	25-50
Stage 4: severe	50-75
Stage 5: critical	>75

CT without concentration iodine contrast. In patients with COVID-19, CT showed characteristic lung parenchyma lesions: peripheral, bilateral ground-glass opacities. These lesions were classified into five stages based on the recommendation of the French Society of Thoracic Imaging.