This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
[{'content': 'Shape of extradural hematoma on NCCT is ? \nSelect and explain. \nA. Medially concave, B. Lens shaped, C. Bean shaped, D. Crescent shaped', 'role': 'user'}, {'content': "Answer: B \nExplanation: CT scan head is diagnostic. Extradural haematoma shows biconvex lesion Ref: SRB's Manual of Surgery, 4th Edition, pg. no. 1177 On CT, extradural haematomas appear as a lentiform (lensshaped or biconvex) hyperdense lesion between skull and brain, constrained by the adherence of the dura to the skull. Ref: Bailey & Love Sho Practice Of Surgery, 26th Edition, pg. no. 315", 'role': 'assistant'}]