After PET CT examination, the patient has only a trace amount of radioactivity in his body, which will not cause any harm to the people around him or medical staff, and only needs to limit his contact with pregnant women, infants and minors, without excessive attention and protection.
Knowing the process of PET CT examination, it is not difficult to understand why there is no need to pay attention to the radioactivity in the patient's body after PET CT examination. After the patient is injected with a tiny amount of radiopharmaceutical, it takes about 60 minutes or so for the distribution in the body to reach equilibrium to fully show the lesions. During this period, the patient needs to drink enough water and urinate many times, and the time for the patient to go on the computer for examination is about 20 minutes, and then he needs to wait for the doctor to evaluate whether the image meets the diagnostic needs before leaving, and the basic consumption time of the whole process is about 100 minutes after the injection of radiopharmaceuticals. At this point, there is very little radioactivity left in the patient's body, and the radiation to the surrounding people is very low.
Even for special patients who need to be accompanied throughout the whole process, the large dose that the accompanying staff receives throughout the whole process is about 016MSV, which is equivalent to the amount of cosmic ray radiation exposed to by flying from Shanghai to Washington D.C. (about 19 hours of flight time), will not affect human health itself, so there is no need to worry too much.