system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Investigation of choice in gall bladder stone is:
assistant
The correct answer is  Ans: a (USG)Ref: Bailey & Love, 24th ed, p. 1097 & 23rd ed, p. 968