Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Increased airspace opacity of the lung base bilaterally may reflect atelectasis , however infection in the appropriate clinical setting is a reasonable alternative . The cardiac , hilar and mediastinal contours are normal . No pleural abnormality is seen . Foreshortened left distal clavicle , from prior resection .
    OUTPUT:
    
Bibasilar airspace opacities likely represent atelectasis , however may be infectious in the appropriate clinical setting .