Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal and hilar contours are stable , with median sternotomy wires and aortic valve replacement in standard position . A small amount of anterior mediastinal air persists , expected in the post-operative setting . There are small bilateral pleural effusions . There is no pneumothorax . Lungs are well expanded and clear . The vasculature is within normal limits .
    OUTPUT:
    
Small bilateral pleural effusions .