Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate low lung volumes , which accentuate bronchovascular markings . Cardiac and mediastinal silhouettes are unchanged . Moderate cardiomegaly is stable . Pacemaker leads are unchanged in position . The patient is status post median sternotomy and CABG . Right lung base opacities are slightly more conspicuous since prior . There is mild pulmonary edema , slightly improved since ___ .
    OUTPUT:
    
1 . Stable cardiomegaly . Slight interval improvement in mild pulmonary edema . 1 . Right lung base opacities , slightly more conspicuous since ___ , which may relate to low lung volumes , represent atelectasis or infection in the appropriate clinical setting .