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': 'Which one of the following is a recognized X-Ray feature of rheumatoid ahritis? \nSelect and explain. \nA. Juxta-aicular osteosclerosis, B. Bamboo spine, C. Bone erosions, D. Peri-aicular calcification', 'role': 'user'}, {'content': "Answer: C \nExplanation: Rheumatoid ahritis is an autoimmune disease characterized by symmetric progressive polyahritis. Inflammation of synovium cause cailage destruction, and bone erosion. Bone erosion is the characteristic x-ray finding in a case of rheumatoid ahritis(RA). Xray findings in RA includes: Uniform joint space narrowing, symmetric joint involvement, marginal bone erosions, ulnar detion of phalanges, radial detion of radiocarpal joint, involvement of joints such as MCP, PIP and carpal. Ref: Physical Medicine and Rehabilitation Board Review By Sara J. Cuccurullo, Page 111; Examination Medicine By Nicholas Tailey, Simon O'Connor, Page 347; Differential Diagnosis in Conventional Radiology By Francis A. Burgener, 3rd Edition, Page 192-4.", 'role': 'assistant'}]