Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . The heart is borderline in size . The cardiac , mediastinal and hilar contours are otherwise unremarkable aside from aortic calcification . There is a patchy opacity obscuring the left lung base , probably due to atelectasis , although not entirely specific . It is possible that there may be a very small coinciding pleural effusion on the left only . None is suspected on the right . No fracture is identified .
    OUTPUT:
    
No evidence of injury or acute cardiopulmonary disease .