Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Low lung volumes . Bibasilar atelectasis . Lungs are otherwise clear . No pleural effusion or pneumothorax is seen . Mild degenerative changes of the visualized spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .