Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is top normal . The hilar and mediastinal contours are normal . There is mild bibasilar atelectasis . There is no large pleural effusion or pneumothorax . Note is made of an old healed left fifth rib fracture .
    OUTPUT:
    
Mild bibasilar opacities are likely secondary to atelectasis .