This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acoustic Neuroma, Subject name: ENT
[{'content': 'Acoustic neuroma of 1 cm diameter, the investigation of choice: \nSelect and explain. \nA. CT scan, B. MRI scan, C. Plain X-ray skull, D. Air encephalography', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (b) MRI scan(Ref. Cummings, 6th ed., 2751)The gold standard investigation for the diagnosis of acoustic neuroma is gadolinium enhanced MRI. Even very small asymptomatic lesions can be observed by MRI.', 'role': 'assistant'}]