Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded with left - greater - than - right linear bibasilar airspace opacities most likely atelectasis , however infectious process would be difficult to exclude . Trace pleural effusions are noted without pneumothorax . The heart is mildly enlarged with normal cardiomediastinal contours . Sternotomy wires are intact .
    OUTPUT:
    
Bibasilar opacities most likely atelectasis though infection can not be excluded .