Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been mild improvement in the right pleural effusion status post thoracentesis , however , with still a mild - to - moderate amount of fluid remaining . There is no pneumothorax . There is otherwise no significant change compared to exam from two hours prior .
    OUTPUT:
    
Minimal improvement of persistent mild - to - moderate right pleural effusion status post thoracentesis without evidence of pneumothorax .