This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal system, Subject name: Radiology
[{'content': 'Based upon this PA ulnar detion view of the wrist, what is the MOST likely diagnosis? \nSelect and explain. \nA. Osteomyelitis, B. De Quervain tenosynovitis, C. Hyperophic osteoahropathy, D. Rheumatoid ahritis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There is focal periostitis at the radial styloid. The radial styloid itself is normal. This is secondary to adjacent inflammation at the extensor pollicis brevis and abductor pollicis longus tendons (De Quervains tenosynovitis). The periosteal reaction of osteomyelitis is usually associated with abnormal underlying bone. The periosteal reaction of hyperophic osteoahropathy is more diffuse involving both the radius and ulna. New bone formation is not a feature of rheumatoid ahritis.', 'role': 'assistant'}]