This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
Best method of localization of insulinoma:- 
Select and explain. 
A. EUS with intra-operative palpation, B. MRI with dynamic CT, C. SRS, D. CECT
A: EUS with intra-operative palpation
Answer: A: EUS with intra-operative palpation 
Explanation: Localization of insulinoma Gold Standard Investigation - 72 hours fasting Insulin/ Glucose (ratio) > 0.4 is diagnostic Best pre-op Test for localization- Intra Aerial Ca+ injection with poal venous blood sampling Overall best Investigation for localization - EUS along with "Intra-Op Palpation"