Disease Interlobular Septa This image is a panoramic view of the lung showing almost rectangular secondary lobules surrounded by interlobular septa (cream borders) The distal bronchioles (teal) and pulmonary arteriole (royal blue are shown in the centre of a lobule in the right lower corner. The branches of these two structures are shown in the secondary lobule with the acinar airways shown in teal and the presumed course artistically inferred in royal blue. Within the interlobular septa (light pink) remnants of the pulmonary venules (red – inferred) and lymphatics (yellow inferred) course going in the opposite direction to the arteriole and the airways. Courtesy Armando Fraire MD. Keywords:lung pulmonary alveoli alveolus secondary lobule interlobular septa vein lymphatic histology interstitium interstitial normal copyright 2020 all rights reservedCourtesy of: Armando Fraire, M.D. Sarcoidosis CT WITH SUBPLEURAL AND LYMPHOVASCULAR NODULES IN THE RIGHT UPPER LOBE – INTERLOBULAR SEPTA AND CENTRILOBULARSARCOIDOSIS, ACTIVE – ALVEOLAR FORM Ashley Davidoff MD CT OF THE SECONDARY LOBULE WITH LYMPHOVASCULAR NODULES IN INTERLOBULAR SEPTA (blue arrows) AND CENTRILOBULAR REGION (red arrows)Ashley Davidoff MD CHF CHF – Alveolar EdemaCT scan shows Diffuse ground glass pattern with thickening of the interlobular septa and manifesting as crazy paving patternAshley Davidoff MD Pulmonary Alveolar Proteinosis Crazy-paving sign. Axial CT of the chest shows thickening of the intralobular and interlobular septa with a superimposed background of ground-glass opacity in a patient with pulmonary alveolar proteinosis. Source Signs in Thoracic Imaging Journal of Thoracic Imaging 21(1):76-90, March 2006. ILD CRAZY PAVING IN ILD Crazy paving in ILD is a CT feature of interstitial lung disease and is characterised by diffuse ground glass caused by a combination of interlobular septal and intralobular septal thickening resulting well demarcated patchy densities in the lungs.