Thin-section CT findings were interpreted using the descriptors proposed by the Fleischer Society Nomenclature Committee (16) . Ground-glass opacity (GGO) was defined as an increase in the lung parenchymal attenuation that did not obscure the underlying vascular architecture. A nodule was defined as round opacity, at least moderately well-defined, and no more than 3 cm in diameter. Consolidation was defined as increased lung attenuation that obscured the underlying vasculature (16) . The lesion size was described as small (diameter, less than 1 cm), medium (diameter, 1 to 3 cm), large (diameter, 3 cm to 50% of the segment), or segmental (50% to 100% of the segment). The sites were described by the name and number of involved segments of the lung. Location of the lesion was defined as peripheral if it was in the outer onethird of the lung; otherwise, it was defined as central (17) . Attention was also paid to the presence of other abnormalities such as pleural effusion, lymphadenopathy, cavitation, calcification, or septal thickening.