Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Upright AP radiographs of the chest demonstrate minimal bibasilar atelectasis but otherwise clear lungs . The hilar and cardiomediastinal contours are normal . There is no pneumothorax or pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
Minimal bibasilar atelectasis . No acute cardiopulmonary process .