Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes limit assessment of the lung bases . Additionally , the cardiac silhouette size is likely exaggerated by low lung volumes , but remains unchanged , and appears mildly enlarged . The mediastinal contour is stable . There is crowding of the bronchovascular structures , but no overt pulmonary edema . Streaky opacities in the lung base , this may reflect atelectasis . Infection can not be excluded . No large pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes limit assessment of the lung bases . Likely bibasilar atelectasis , though infection can not be excluded .