Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . The patient is status post median sternotomy and cardiac valve replacement . Mediastinal contours are stable . There is againmild prominence of the main pulmonary artery . The cardiac silhouette is top normal . There is mild diffuse increase in interstitial markings bilaterally , which may be due to mild interstitial edema . No large pleural effusion is seen . There is no pneumothorax .
    OUTPUT:
    
Mild interstitial edema .