This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hepatobiliary radiology, Subject name: Radiology
[{'content': 'Investigation of choice for Acute cholecystitis is: \nSelect and explain. \nA. H.I.D.A Scan, B. USG, C. CT Scan, D. Biopsy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: IOC for Acute Cholecystitis: USG USG is the IOC for most GB pathologies Most Accurate Investigation for Acute Cholecystitis: H.I.D.A Scan (H.I.D.A is used for equivocal cases where USG is not conclusive ) IOC for Abdominal trauma :CECT', 'role': 'assistant'}]