Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 04 :30 is submitted .
    OUTPUT:
    
Endotracheal tube and right internal jugular central line are unchanged in position . A nasogastric tube is seen coursing below the diaphragm with the tip not identified . Lung volumes remain low with layering bilateral effusions and bibasilar airspace opacities consistent with partial lower lobe atelectasis . Underlying pneumonia can not be excluded . Overall , pulmonary edema has improved . No obvious pneumothorax . Heart remains stably enlarged .