Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is dense retrocardiac opacity with silhouetting of the left hemidiaphragm . There is mild pulmonary edema . No large right pleural effusion . Cardiac silhouette is enlarged but similar compared to prior . Atherosclerotic calcifications seen at the aortic arch . Median sternotomy wires are also noted .
    OUTPUT:
    
Dense retrocardiac opacity which could be due to any combination of atelectasis , consolidation or effusion . Mild pulmonary edema .