This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Esophageal Perforation, Subject name: Surgery
Investigation of choice for esophageal rupture is? 
Select and explain. 
A. Dynamic MRI, B. Rigid esophagoscopy, C. Barium contrast swallow, D. Water soluble low molecular weight contrast swallow
D: Water soluble low molecular weight contrast swallow
Answer: D: Water soluble low molecular weight contrast swallow 
Explanation: ANSWER: (D) Water soluble low molecular weight contrast swallowREF: with textUse of non ionic water soluble contrast medium instead of barium is warranted when there is any risk of aspiration or esophageal leak. (Ref: Gastrointestinal Imaging: The Requisites By Giles W. Boland 4th ed page 2)Careful endoscopic assessment at the end of any procedure combined with a chest X-ray will identify many cases of perforation immediately. If not recognised immediately, then early and late suspected perforations should be assessed by a water-soluble contrast swallow. If this is negative, a dilute barium swallow should be considered. A CT scan can be used to replace a contrast swallow or as an adjunct to accurately delineate specific fluid collections. (Bailey 25th ed page 1015)Diagnosis of an esophageal perforation may be made radiographically. A chest roentgenogram may demonstrate a hydropneumothorax. A contrast esophagram is done using barium for a suspected thoracic perforation and Gastrografin for an abdominal perforation. Barium is inert in the chest but causes peritonitis in the abdomen, whereas aspirated Gastrografin can cause life-threatening pneumonitis. A surgical endoscopy needs to be performed if the esophagram is negative or if operative intervention is planned. (Ref: Sabiston 18th ed chapter 41)