Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is top - normal in size . The cardio mediastinal and hilar contours are within normal limits . The lungs are clear . Median sternotomy wires are unchanged in appearance . There is a small left pleural effusion . No pneumothorax .
    OUTPUT:
    
Small left pleural effusion . No other acute cardiopulmonary process