Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . There is slight unfolding of the thoracic aorta . The heart is at the upper limits of normal size . There is a patchy right medial basilar opacity suggestive of atelectasis . Otherwise , the lungs appear clear without evidence for congestive heart failure . There is no pleural effusion or pneumothorax . There is mild relative elevation of the right hemidiaphragm . Healed right - sided posterior fourth through sixth rib fractures appear unchanged . There has been no significant change .
    OUTPUT:
    
No evidence of acute disease .