Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large right pleural effusion , which obscures the right heart border . There is no mediastinal shift indicating underlying associated atelectasis . The mediastinal silhouette and pulmonary vasculature are unremarkable . The left lung is clear . There is no pneumothorax .
    OUTPUT:
    
Large right pleural effusion , increased since prior .