Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without pleural effusion or pneumothorax . The cardiac silhouette remains mildly enlarged . Tortuosity of the aorta results in mild mediastinal widening , though this is unchanged from ___ . The pulmonary vasculature is normal . There are changes of median sternotomy .
    OUTPUT:
    
No acute chest abnormality with unchanged appearance to tortuosity of the aorta .