Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to ___ , the left lower lobe atelectasis has improved . However there is only mild improvement in the bilateral pulmonary edema . No pleural effusions . No pneumothorax . The heart is mildly enlarged but unchanged . Mediastinal contours are unchanged .
    OUTPUT:
    
Significant improvement in left lower lobe atelectasis . Mild improvement in bilateral pulmonary edema .