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': 'Gamma camera in Nuclear Medicine is used for – \nSelect and explain. \nA. Organ imaging, B. Measuring the radioactivity, C. Monitoring the surface contamination, D. RIA', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A gamma camera is a camera that records the distribution of a radioactive chemical\xa0that is taken up by a specific\xa0organ or tissue of interest.\xa0Nuclear medicine studies require the oral or intravenous introduction of very low - level radioactive chemicals\xa0(called radionuclides, radiopharmaceuticals or radiotracers) into the body.\xa0\nThe radionuclides are taken up by the organs in the body and then emit faint\xa0gamma-ray signals, which are\xa0measured by a gamma camera.', 'role': 'assistant'}]