Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to chest radiographs dated ___ , there is new complete opacification of the left hemithorax with rightward mediastinal shift caused by a large pleural effusion , which has substantially increased in size since ___ . The left pleural masses seen on prior radiographs and CT are obscured by the pleural fluid . The partially calcified right upper lobe nodule is unchanged .
    OUTPUT:
    
Large left pleural effusion causing complete opacification of the left hemithorax and rightward mediastinal shift .