Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are normally expanded and clear . The cardiomediastinal silhouette , hilar contours , and pleural surfaces are normal . There is no pleural effusion or pneumothorax . There is increased leftward displacement of the trachea which may reflect enlargement of the thyroid .
    OUTPUT:
    
No acute cardiopulmonary abnormality . Increase leftward displacement of the trachea may reflect known enlargement of the thyroid .