Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperexpanded , with biapical hyperlucency , flattening of the hemidiaphragms , and widening of the retrosternal clear space . Improved aeration of the left lung , and right middle lobe atelectasis persists . Changes of median sternotomy , mediastinal clips , and coronary artery bypass grafting are again seen . Heart size is normal . Resolved bilateral pleural effusions .
    OUTPUT:
    
1 . Resolved pleural effusions . 2 . Chronic obstructive airways disease .