Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is interval improvement in the previously demonstrated left pleural effusion . No focal pneumonia , pneumothorax , or pulmonary edema is seen . There is continued left lower lobe atelectasis which is unchanged since the prior study . Post-operative cardiac enlargement is also unchanged .
    OUTPUT:
    
Improving left pleural effusion . Otherwise , no significant change since the prior study .