Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is normal . Mediastinal and hilar contours are unchanged . Crowding of the bronchovascular structures is present without overt pulmonary edema . Patchy opacities in the lung bases may reflect areas of atelectasis though infection is difficult to exclude . No pleural effusion or pneumothorax is present . Mild to moderate multilevel degenerative changes are seen in the thoracic spine .
    OUTPUT:
    
Low lung volumes with patchy bibasilar airspace opacities , potentially atelectasis but infection is not excluded .