IMPRESSION:
1.  Standard positioning of lines and tubes.
 2.  Low lung volumes with left upper lung and bibasilar opacification,
 possibly representing atelectasis. Possible small left pleural effusion.
 3.  Superior mediastinal widening may be due to low lung volumes and supine
 positioning though a chest CTA can be performed for further evaluation if
 there is concern for mediastinal injury.
 4.  Irregularity of the right seventh rib laterally and a fracture in this
 region is not excluded.