Chest radiograph (A) shows a large right pleural mass with incomplete margin sign, obtuse angle of interface with the chest wall, and caudad drooping. Axial computed tomography (CT) scan of the chest (B) shows a right lateral pleural loculated collection of pleural effusion with a small anterior gas-liquid level and contrast-enhancing visceral and parietal pleura yielding the "split pleura" sign. Coronal reformat (C) confirms the right loculated pleural empyema with slight enhancement of the adjacent pleura.
