This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
[{'content': 'True about MRI are all except \nSelect and explain. \nA. Not helpful in a breast implant, B. Not good for calcified lesions, C. No radiation exposure, D. Contraindicated in cardiac pacemaker', 'role': 'user'}, {'content': 'Answer: A \nExplanation: "MRI should be used (with mammography and ultrasound) to investigate any nodular change near a breast implant\xa0to determine whether it is caused by a tumor or by silicon leak"', 'role': 'assistant'}]