Subpleural interstitial thickening 2016-12-04T19:44:43Z Subpleural scarring Subpleural interstitial thickening can be difficult to recognize where the lung contacts the chest wall or mediastinum but is easy to delineate adjacent to the major fissure. Thickening of the fissure visible on high-resolution computer tomography may represent subpleural interstitial thickening. Increase in thickness of the subpleural interstitium. Abnormal subpleural morphology