Crazy paving refers to a pattern seen on computed tomography of the chest, involving lobular septal thickening with variable alveolar filling. The finding is seen in pulmonary alveolar proteinosis,[1] and other diseases.[2] Its name comes from its resemblance to irregular paving stones, called crazy pavings.[3]
There are variety of causes for crazy paving patterns: infection, cancer, blood related disorders, diseases caused by inhalation of particles, and idiopathic disease. Specific lung disorders that can cause such patterns are: pneumocystis pneumonia, mucinous bronchioloalveolar carcinoma, pulmonary alveolar proteinosis, sarcoidosis, nonspecific interstitial pneumonia, organizing pneumonia, exogenous lipoid pneumonia, adult respiratory distress syndrome, and pulmonary hemorrhage syndromes.[4]