Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear , however mild bronchial wall thickening may be due to acute or chronic bronchitis . The cardiac , hilar and mediastinal contours are normal . No pleural abnormality is seen .
    OUTPUT:
    
Mild bronchial wall thickening may be due to acute or chronic bronchitis . No pneumonia .