Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal with mild tortuosity of a calcified aortic arch . Mediastinal silhouette and hilar contours are otherwise unremarkable . There is mild bibasilar atelectasis . Lungs are otherwise clear . Pleural surfaces are clear without effusion or pneumothorax . No definite fracture is identified . Note is made of mild elevation of the left hemidiaphragm .
    OUTPUT:
    
1 . No definite traumatic findings . Rib series may be helpful if there is focality . 2 . Mild bibasilar atelectasis . 3 . Mild elevation of the left hemidiaphragm of unclear significance .