For CT analysis, image interpretation was performed by a radiologist (in consultation with the scientific team) having more than ten years of diagnostic experience along with formal certifications by the American Board of Radiology (ABR) and the American Board of Nuclear Medicine (ABNM). Lesions on CT were identified using conventional criteria and terminology; Ground-glass opacity (GGO) is defined in this study as hazy increased lung opacity, with discernible underlying lung architecture such as visible bronchial and vascular structures, representing partial displacement of air in interstitial and alveolar airspaces; Consolidation is defined in this study as high density lung lesions (more dense than GGO) in which vascular and bronchial margins are obscured, representing complete displacement of alveolar air [27] .