Ground-glass opacification 2016-12-04T19:55:32Z Ground-glass opacification is a non-specific sign and can be observed with many conditions including infection, chronic interstitial disease and acute alveolar disease. See Figure 2 of Hansell DM, et al., Fleischner Society: glossary of terms for thoracic imaging. Radiology. 2008;246:697-722. Ground-glass opacification on pulmonary HRCT Ground glass opacities GGO On chest radiographs, ground-glass opacity appears as an area of hazy increased lung opacity, usually extensive, within which margins of pulmonary vessels may be indistinct. On CT scans, it appears as hazy increased opacity of lung, with preservation of bronchial and vascular margins. It is caused by partial filling of airspaces, interstitial thickening (due to fluid, cells, and/or fibrosis), partial collapse of alveoli, increased capillary blood volume, or a combination of these, the common factor being the partial displacement of air. Ground-glass opacity is less opaque than consolidation, in which bronchovascular margins are obscured. Pulmonary opacity