Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Emphysematous changes are re- demonstrated . The lung volumes are decreased compared to the prior study . Cardiac , mediastinal and hilar contours are unchanged . There is no pulmonary vascular congestion . Patchy bibasilar airspace opacities likely reflect atelectasis . No pleural effusion or pneumothorax is present . Old bilateral rib fractures are again noted .
    OUTPUT:
    
Bibasilar atelectasis . Emphysema .