Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Paucity of the vessels , particularly in the upper lobes , are suggestive of emphysema . The lungs are fully expanded and clear . Cardiomediastinal and hilar silhouettes are normal . Pleural surfaces are normal . Median sternotomy wires are unchanged since ___ .
    OUTPUT:
    
Stable emphysema . No evidence of pneumonia . No acute cardiopulmonary process .