Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to prior chest x-ray , persistent large right lung effusion , minimally decreased since chest x-ray of 7 : 48 a .m . Left lung is still clear . Heart size is normal . There is no pneumothorax . Right base pleural drain is unchanged in position .
    OUTPUT:
    
Minimal interval decrease of multi-loculated right pleural effusion , which is still large .