Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . Patchy opacities in the lung bases likely reflect atelectasis . Cardiac , mediastinal and hilar contours are normal . No large pleural effusion or pneumothorax is identified on this supine exam . Several acute mildly displaced rib fractures are again seen on the left .
    OUTPUT:
    
Bibasilar atelectasis . Mildly displaced left - sided rib fractures . No pneumothorax is identified .