Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperinflated but clear . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is normal in size .
    OUTPUT:
    
1 . No acute cardiopulmonary process . 2 . Pulmonary hyperinflation , which may reflect emphysema or small airway obstruction .