Computerized tomographic recognition of visceral pleural changes.

Pathology of the visceral pleura seen by CT of the lung can be separated from the underlying lung parenchyma by using appropriate CT window viewing settings. A wide window setting permits both pleura and lung parenchyma to be examined simultaneously. The use of mediastinal window setting (i.e., soft tissue) showed the smooth inner surface of parietal pleural fibrosis or plaque formation lying parallel or convex to the associated rib cage, whereas the thickened or calcified visceral pleura had an irregular inner surface with single or multiple protrusions penetrating the underlying lung substance and retraction of the associated pathological visceral pleural surface. We present cases of tuberculous calcified visceral pleura, a talc pleuritis and carcinoma abutting on the interlobar fissure, and clearly demonstrate the CT features.