Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 15 :56 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 . Overall , the lungs are unchanged in appearance with layering left effusion and bibasilar opacities suggestive of atelectasis , although pneumonia can not be excluded . Lung volumes are low with crowding of the pulmonary vasculature but no overt pulmonary edema . No obvious pneumothorax .