Pleural Thickening and Calcification

Pleural thickening and calcification discusses the radiographic and computed tomography (CT) manifestations of benign pleural thickening and pleural calcification. Benign pleural thickening must be differentiated from malignant pleural thickening and their differentiating characteristics will be discussed. Pleural plaque is the most common manifestation of asbestos exposure and carries no risk of malignant degeneration. The most common imaging appearance is bilateral sharply demarcated, multifocal areas of discontinuous pleural thickening that often calcifies over time. Pleural plaques spare the apical and costophrenic sulcus pleura and has a predilection for the diaphragmatic pleura. Diffuse pleural thickening is associated with hemothorax, empyema, connective tissue disorders, and asbestos exposure. It is generally unilateral, causes blunting of the costophrenic angle, spans multiple rib interspaces, and is irregular in shape. When diffuse pleural thickening calcifies and is associated with volume loss in the affected lung, it is termed fibrothorax.