Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 19 :54 is submitted .
    OUTPUT:
    
Right internal jugular Swan - Ganz catheter , endotracheal tube , and mediastinal and chest tubes are unchanged in position . Nasogastric tube is seen coursing below the diaphragm with the tip not identified . The patient is status post median sternotomy for CABG with expected postoperative cardiac and mediastinal contours . Interval improvement in aeration of the left lung but persistent mild to moderate pulmonary and interstitial edema . Layering left effusion with more focal patchy airspace disease at the left base favoring atelectasis , although pneumonia can not be excluded . No obvious pneumothorax .