Non-specific interstitial pneumonia showing a "crazy paving" pattern on high resolution CT.

Non-specific interstitial pneumonia is characterized pathologically by uniform interstitial inflammation and fibrosis. This disease is most commonly demonstrated on high resolution CT as subpleural ground-glass opacity mixed with irregular linear opacities. The authors report a case of non-specific interstitial pneumonia with high resolution findings consistent with a "crazy paving pattern". This appearance, represented by smoothly thickened interlobular septa with a background of geographic areas of ground-glass opacity, is unusual for non-specific interstitial pneumonia and was indistinguishable from other interstitial or alveolar lung diseases.