Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette and hilar contours are unremarkable . Lung volumes are low with mild bibasilar atelectasis . The lungs are otherwise clear . Pleural surfaces are clear without large pleural effusion or pneumothorax . There are multiple bilateral old appearing rib fractures .
    OUTPUT:
    
No acute cardiopulmonary abnormality .