Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery and mitral valve repair . There is still marked enlargement of the right hemidiaphragm but atelectasis at the right lung base has decreased and appears minimal . The left lung appears clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Elevation of the right hemidiaphragm . No evidence of acute disease .