This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'MRI is the investigation of choice in all of the following complications of CSOM except: \nSelect and explain. \nA. Extradural abscess, B. Bezold abscess, C. Coalescent mastoiditis, D. Cerebral abscess', 'role': 'user'}, {'content': "Answer: C \nExplanation: MRI gives little information in bone disease and is not useful in coalescent mastoiditis' in which CT scan would be the investigation of choice. It shows bone destruction and coalescence of mastoid air cells. In Bezold abscess, size, extent and location of abscess in soft tissues can be appreciated.Similarly, extradural abscess and cerebral abscess are better appreciated in MRI.", 'role': 'assistant'}]