This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
Investigation of choice for obstructive jaundice: 
Select and explain. 
A. CXR, B. USG, C. CT, D. MRI
B: USG
Answer: B: USG 
Explanation: Ans: b (USG) Ref: Bailey, 24thUSG is the first investigation in a case of obstructive jaundice for visualising gall stones, liver tumours, dilated bile ducts.ERCP is the gold standard for CBD stones as it provides therapeutic option at the time of diagnosis.