This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Imaging and basics in Ohopedics, Subject name: Orthopaedics
[{'content': 'A 5year-old child complains of pain and swelling of the right tibia. On laboratory evaluation he has elevated ESR and leucocytosis X-ray shows a tibial lesion. Which of the following is the best investigation which can help us clinch the diagnosis: \nSelect and explain. \nA. Blood C/S, B. Pus C/S, C. MRI, D. Biopsy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Diagnostic is always Tissue Diagnosis -Tumors and infection can mimic each other (clinically and radiologically), e.g. Osteosarcoma and Ewings sarcoma are two tumors that mimic osteomyelitis. (Both have accompanying fever and increased local temperature). -Tumors and bone infections are usually metaphyseal and both need tissue diagnosis for differentiation. Thus, Culture is gold standard for infection -Histopathology is gold standard for tumors So rule is Culture all biopsies, biopsy all cultures.', 'role': 'assistant'}]