Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal with mild tortuosity of the thoracic aorta . Mediastinal silhouette and hilar contours are unremarkable . The lungs are mildly hyperinflated with flattening of the hemidiaphragms suggestive of COPD . Lungs are clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic abnormality . Mild hyperinflation suggestive of COPD .