This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroradiology, Subject name: Radiology
[{'content': 'A 35 year old female presented with history of multiple transient ischemic attacks. The Given Carotid angiogram is suggestive of \nSelect and explain. \nA. Atherosclerosis, B. Fibromuscular dysplasia, C. Thrombosis, D. Carotid dissection', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Beaded or toous appearance of internal carotid aery Fibromuscular dysplasia Characterised by an idiopathic, non-inflammatory,non-atherosclerotic angiopathy of small and medium-sized aeries. More common in young women, typically diagnosed between the ages of 30 and 50 DSA is the gold standard. The characteristic findings alternating stenosis and dilatations, causing a String of beads appearance.', 'role': 'assistant'}]