Pulmonary interstitial high-resolution computed tomography abnormality Crazy paving pattern 2017-04-22T12:57:46Z HP:0033659 Crazy-paving pattern The so-called crazy paving pattern appears as thickened interlobular septa and intralobular lines superimposed on a background of ground-glass opacity, resembling irregularly shaped paving stones. The crazy-paving pattern is often sharply demarcated from more normal lung and may have a geographic outline. It was originally reported in patients with alveolar proteinosis and is also encountered in other diffuse lung diseases that affect both the interstitial and airspace compartments, such as lipoid pneumonia. See Figure 20 of Hansell DM, et al., Fleischner Society: glossary of terms for thoracic imaging. Radiology. 2008;246:697-722. Crazy paving pattern on pulmonary HRCT