Fig. 4From: Impact of COPD on clinical and CT characteristics of COVID-19-associated pneumonia: single tertiary center experienceIllustration of total lung scores of patients in the COPD group shown on axial CT images. A CT 1 (mild), < 25% involvement. B CT 2 (moderate), 25–50% involvement. C CT 3 (medium-to-severe), 50–75% involvement. D CT 4 (severe), > 75% involvement. COPD—chronic obstructive pulmonary disease; CT—computed tomographyBack to article page