Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph ___ at 02 : 18 is submitted .
    OUTPUT:
    
Stably enlarged postoperative cardiac and mediastinal contours status post median sternotomy . There has been slight interval worsening of mild to moderate interstitial and pulmonary edema . The right hemidiaphragm remains slightly elevated of uncertain significance . No pneumothorax .