Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Comparison with chest radiograph from ___ , a small right effusion has improved . Left pleural effusion with left retrocardiac atelectasis is grossly unchanged . There is persistent moderate central vascular congestion . Moderate cardiomegaly is unchanged . Patient is status post median sternotomy .
    OUTPUT:
    
Grossly stable large left pleural effusion with overlying atelectasis . Trace right pleural effusion appears improved .