Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size , mediastinal and hilar contours are normal . Lungs are clear , and there are no pleural effusions or acute skeletal findings . Chronic bronchial wall thickening is present , and may be due to history of COPD .
    OUTPUT:
    
No radiographic evidence of pneumonia . Chronic bronchial wall thickening , which may be due to history of COPD .