This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Radiology
[{'content': 'Imaging tool of choice for GD? \nSelect and explain. \nA. DWI MRI with ADC maps, B. HMPAO SPECT, C. MR Spectroscopy, D. PET', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans ACreutzfeldt-Jacob disease is a spongiform encephalopathy caused by prions. On MRI T2 hyperintensity in basal ganglia, thalamus (Hockey stick sign), cortex and white matter with persistent diffusion restriction in considered most sensitive sign. On PET scan there can be hypometabolsim in affected area however it is less sensitive', 'role': 'assistant'}]