Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright chest radiograph ___ at 07 :33 is submitted .
    OUTPUT:
    
Endotracheal tube , right internal jugular Swan - Ganz catheter , nasogastric to and mediastinal and pleural tubes remain unchanged in position . Interval improvement but residual mild pulmonary and interstitial edema . Status post median sternotomy with expected postoperative cardiac and mediastinal contours . Left basilar retrocardiac opacity likely reflects atelectasis in the setting of small effusion . No obvious pneumothorax .