Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear unchanged . There is no pleural effusion or pneumothorax . The lungs appear clear aside from minimal left basilar opacity , most suggestive of minor atelectasis , which has decreased .
    OUTPUT:
    
No evidence of acute cardiopulmonary disease .