Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy , CABG , and mitral valve replacement , with sternotomy wires that appear intact and appropriately aligned . Stable appearance of the postoperative mediastinum . Stable mild enlargement of the cardiac silhouette . The pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is seen .
    OUTPUT:
    
No evidence of pneumonia .