A retrospective review of the medical records of our radiological computed tomography database was performed, from 1 January 2008 until 31 December 2008, searching for patients reported to have a "crazy-paving" pattern on a CT of the chest. In total, 98 patients with a crazy-paving pattern were retained and reviewed. To rule out acute pulmonary embolism, most of the patients underwent interstitial pathological features or underwent their chest CT in an oncological setting. All these patients underwent a dedicated MDCT of the chest with 100 mAs, Fig. 1 a Anatomy of the secondary pulmonary lobule. b-e The reticular pattern: b thickening of the interlobular septa; c thickening of the intralobular interstitium; d irregular areas of fibrosis; e periacinar pattern 120 kV, slice thickness of 1 and 3 or 5 mm, and table feed of 12 mm per rotation, with or without intravenous contrast administration, according to the indication of chest CT. Only seven patients with a crazy-paving pattern on chest CT also underwent an open lung biopsy to make the definitive diagnosis. In 59 patients, the definitive diagnosis was made on a clinical basis. In the remaining 32 patients, the cause of the crazy-paving pattern remained undecided, because patients were not followed further in our institution.