Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large pleural effusion on the right with presumed associated collapse of the right middle and lower lobes . There is no net mediastinal shift . The left lung remains clear . The recent prior MRCP showed only a small right - sided pleural effusion .
    OUTPUT:
    
Large pleural effusion on the right , appearing over a short interval .