Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Evaluation is limited due to the presence and superimposition of external metallic devices . Cardiomediastinal contours are unchanged . The lungs are grossly clear . There is no pneumothorax . Left pleural effusion is small . Sternal wires are aligned . Patient is status post CABG and AVR
    OUTPUT:
    
No pulmonary edema or pneumonia . Small left effusion increased from prior