Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates slight retrocardiac opacity consistent with atelectasis . There has been marked interval improvement in bilateral interstitial opacities consistent with improving pulmonary edema . The mediastinum remains widened , although has decreased slightly in size as compared to the prior . The heart is mildly enlarged . There is no pneumothorax . A chest tube projects over the right hemithorax . There is a stent in the decending thoracic aorta .
    OUTPUT:
    
Marked interval improvement in now interstitial pulmonary edema .