Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with the prior study , new left lower lung opacity may be a combination of atelectasis and pleural fluid , however superimposed infection is not excluded . Right basilar opacity is similarly detected . Mild cardiomegaly is unchanged . No pneumothorax . Intact median sternotomy wires and unchanged positioning of multiple mediastinal surgical clips .
    OUTPUT:
    
New bibasilar opacities are more concerning for vascular congestion , given cardiomegaly . However , superimposed infection is not excluded in the correct clinical setting .