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: Surgery
[{'content': 'Thoracic outlet syndrome is primarily diagnosed by: \nSelect and explain. \nA. Clinical Evaluation, B. CT scan, C. MRI, D. Angiography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: • TOS refers to compression of subclavian vessels and nerves of the brachial plexus in the region of the thoracic inlet.\n• Divided into: Vascular forms (Arterial and /or Venous) and Neurogenic forms\n• Compression resulting from TOS is dynamic and best evaluated clinically by mechanical provocative maneuvers\n• Symptoms most commonly develop secondary to neural compromise\n• Middle-aged women\xa0are most commonly affected', 'role': 'assistant'}]