Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP upright portable view of the chest was obtained . Patient is status post median sternotomy . Enlargement of the cardiomediastinal silhouette is stable . No large pleural effusion is seen , although a trace left pleural effusion would be difficult to exclude . Left base atelectasis / scarring is seen . While there may be minimal pulmonary vascular congestion , no overt pulmonary edema is seen .
    OUTPUT:
    
Stable enlargement of the cardiomediastinal silhouette .