Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The hilar and mediastinal contours are normal . The lungs are well expanded and clear . There are no pleural effusions or pneumothorax . There is no gross evidence of free air .
    OUTPUT:
    
No gross evidence of free air , however an upright chest radiograph or CT would be recommended for a thorough evaluation .