Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright chest radiograph demonstrates no significant change in bibasilar opacities likely reflecting a combination of atelectasis and effusion , though left lower lobe pneumonia can not be excluded . The cardiac silhouette is notable for early postoperative enlargement , unchanged . Median sternotomy wires and post-surgical changes of CABG are again noted . A right IJ central venous catheter tip is unchanged in position . Pulmonary vasculature is normal .
    OUTPUT:
    
Bibasilar opacities reflecting a combination of atelectasis and effusion ( left greater than right ) are unchanged .