All Computed tomography (CT) findings of the patients will be assess for the presence of the following recognized CT patterns (12): (1) mediastinal and/or hilar lymph node enlargement; (2) ground-glass opacity; (3) consolidation; (4) nodules <3 cm in diameter; (5) thickening of bronchovascular bundles; (6) linear opacity, including interlobular septal lines and interstitial thickening and (7) features indicating scarring and fibrosis (grouped together) that included traction bronchiectasis, honeycombing, cysts and/or volume loss.