Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A portable frontal chest radiograph again demonstrates multiple sternotomy , a nasogastric tube , endotracheal tube , and left PICC , all of which are unchanged in position . The exam is not significantly changed from prior chest radiograph , and redemonstrates mild cardiomegaly and pulmonary edema , as well as bibasilar atelectasis and a small to moderate left pleural effusion . Right base atelectasis may be slightly improved .
    OUTPUT:
    
Possible minimal improvement in right lower lobe atelectasis . Otherwise unchanged chest radiograph .