The crazy-paving pattern is a non-specific pattern. Initially, this pattern was considered to be highly suggestive of alveolar proteinosis. Nowadays, we can find this pattern in different lung diseases: airspace diseases and interstitial diseases [8] . The crazy-paving pattern consists of scattered or diffuse ground-glass attenuation with superimposition of Fig. 13 Graft-versus-host disease. CT revealed multiple areas of ground-glass attenuation and consolidations. There was also a superimposition of multiple lines: thickened inter-and intralobular septa and intralobular fibrosis Fig. 14 Organising pneumonia. CT showed patchy distribution of areas of ground-glass opacification with the superimposition of thickened interlobular septa a linear pattern. These lines can be: thickened interlobular septa (septal lines), thickened intralobular septa and thickening of the intralobular interstitium (intralobular reticular pattern and intralobular branching lines), or it can be a linear deposition of material within the airspaces at the borders of the acini and the secondary pulmonary lobules (periacinar pattern) [4] .