Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are within normal limits . Lungs are clear . Pulmonary vasculature is normal . No pleural effusion or pneumothorax is demonstrated . Mild degenerative changes are seen in the thoracic spine . No displaced rib fractures are noted .
    OUTPUT:
    
No acute cardiopulmonary abnormality .