Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided AICD is unchanged . Heart size is top - normal with mild unfolding of the thoracic aortic arch . Hilar contours are normal . Lungs are clear . Upper lobes are lucent , suggestive of emphysema . Pleural surfaces are clear without effusion or pneumothorax .
    OUTPUT:
    
No acute cardiopulmonary abnormality . Emphysema .