Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Midline sternotomy wires are again noted . The lungs appear clear . No signs of pneumonia or edema . There is a tiny residual left pleural effusion . No pneumothorax . The cardiomediastinal silhouette is normal . Imaged osseous structures are intact . No free air below the right hemidiaphragm is seen .
    OUTPUT:
    
Small residual left pleural effusion .