Radiographs and CT scans.—Parenchymal opacification of the lungs may or may not obscure the margins of vessels and airway walls (45). Consolidation indicates that definition of these margins (excepting air bronchograms) is lost within the dense opacification, whereas ground-glass opacity indicates a smaller increase in attenuation, in which the definition of underlying structures is preserved (59). The more specific terms consolidation and ground-glass opacity are preferred. (See also consolidation, ground-glass opacity.) [Fleischner Society]