Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Residual small right pleural effusion has improved and is now minimal . There is no pneumothorax . New round opacity in the right middle lung is probably due to rounded atelectasis rather than infection . Left lung is unremarkable . Mediastinal and cardiac contours are normal .
    OUTPUT:
    
1 . Improvement of right pleural effusion , which is now minimal . 2 . New focal round opacity at the right lung base is probably rounded atelectasis rather than infection . No further investigation is needed unless the patient presents infectious symptoms .