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': 'Scintiscan is taken by injecting: \nSelect and explain. \nA. Ethidiol, B. Tc- Pertechnetate, C. Sinograffin, D. Any of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Salivary scan (scintiscan) is taken by injecting Tc – Pertechnetate intravenously. Salivary scan is usually contraindicated in acute inflammatory cases.', 'role': 'assistant'}]