Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval widening of the mediastinum due to vascular engorgement . In addition , there is new bilateral interstitial edema . A possible left pleural effusion and atelectasis obscure the left cardiac and hemidiaphragmatic contours more than the prior day . The small right pleural effusion and basilar atelectasis is unchanged . There is no pneumothorax . The support and indwelling lines are unchanged and in their expected locations .
    OUTPUT:
    
Mild acute congestive heart failure .