Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperexpanded but clear . The hilar and cardiomediastinal contours are normal , with stable top - normal heart size and unfolded aorta . There is no pneumothorax . There is no pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
No acute cardiopulmonary process .