In positron emission tomography (PET), a patient is injected with a radioactive element that produces photons, which are sensed slice by slice.是什么意思_In positron emission tomography (PET), a patient is injected with a radioactive element that produces photons, which are sensed slice by slice.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句