Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild persisting pulmonary edema . Increasing retrocardiac opacity which may represent atelectasis and / or consolidation . No pleural effusion or pneumothorax identified . Patient is status post prior median sternotomy and cardiac valve replacements .
    OUTPUT:
    
Mild pulmonary edema . Increasing retrocardiac opacity may reflect atelectasis and / or consolidation .