Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The has been interval improvement of the left retrocardiac opacity . There is no pleural effusion or pneumothorax . No new focal consolidations are identified . The heart size is top normal . The hilar and mediastinal contours are stable .
    OUTPUT:
    
Interval improvement of the left lower lobe atelectasis . No evidence of pneumonia .