Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Allowing for the differences in the radiographic technique , since ___ , mild - to - moderate bilateral pleural effusions are unchanged ; however , the left lower lung atelectasis has minimally improved . Both lungs are clear . Patient is status post median sternotomy with intact sternal sutures following CABG . Central line through the right internal jugular approach ends at the lower SVC / cavoatrial junction . Top normal heart size , mediastinal and hilar contours are stable .
    OUTPUT:
    
Allowing for the differences in radiographic technique since ___ , mild - to - moderate bilateral pleural effusions are unchanged ; however , the left lower lung atelectasis reflected by increased retrocardiac density has improved .