Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low , which accentuate late the bronchovascular markings ; however , there appears to be slight interval worsening of diffuse bilateral pulmonary edema compared to the prior exam . Moderate cardiomegaly is stable . Pacemaker leads are unchanged in position . The patient is status post median sternotomy and CABG . Bibasilar opacities are likely secondary to atelectasis ; however , a superimposed infectious process can not be excluded . There is no large pleural effusion . There is no evidence of pneumothorax . The visualized osseous structures are grossly unremarkable .
    OUTPUT:
    
1 . Interval increase in mild - to - moderate pulmonary edema . 2 . Retrocardiac opacities likely secondary to atelectasis ; however , a superimposed infectious process can not be excluded .