Any discussion of toxicity aside from dose is a ruse. First of all, we are basically too healthy to go to the hospital every day for a CT scan, and secondly, as a diagnostic treatment, CT is designed by the manufacturer to take into account the possible hazards to the human body. Therefore, in actual use, manufacturers will set up a large number of safety measures to prevent radiation from harming the human body. Finally, there is radiation in CT, but the dose of this radiation is not high enough to affect human health.
First of all, let's talk about what is radiation, radiation is a high-energy particle beam. Generally radiation is divided into ionizing radiation and electromagnetic radiation. Electromagnetic radiation is another name for electromagnetic waves, we use cell phone communication, watch TV, use the computer, use WIFI will produce electromagnetic radiation. Electromagnetic radiation is not harmful to human body. Recently, there are many news reports about some old men and women maliciously damaging the base station, worrying about its radiation. The radiation generated by base stations is actually electromagnetic radiation, and ionizing radiation is not a concept at all. After all, a base station is just a signal tower, not a nuclear reactor.
The principle of CT is to use X-rays to penetrate the human body and then form an image of the inside of the body. So CT produces ionizing radiation. We can see placards at the entrance of CT rooms in hospitals to beware of ionizing radiation. The human body receives a radiation dose of at most 1-2 millisieverts per CT examination. This radiation dose is quite tiny and negligible. And when the CT machine is turned off, the radiation is non-existent. So a single CT is not very harmful to the body. On the contrary the doctor can determine the cause of your illness as soon as possible through the results of the CT. Then give you better treatment.
Our fear of radiation comes from three events. First, the U.S. bombing of Japan with the atomic bomb. Second, the Chernobyl nuclear accident in the Soviet Union. Third, the Fukushima nuclear accident in Japan. These three nuclear accidents have made people have a considerable air force for nuclear radiation. But all fear comes from the unknown, it is because we do not know about nuclear radiation, so we will feel nuclear radiation is very scary.
First of all, radiation is everywhere in our daily lives. Let's start with our sun, the surface of the sun is constantly undergoing nuclear fusion all the time. People can understand that the surface of the sun is constantly conducting hydrogen bomb explosions. Since the temperature and pressure on the surface of the sun are sufficient, the fusion reaction of the hydrogen bomb can go on and on. We all know that sunlight has a spectrum, with red light at one end of the spectrum and violet light at the other. Violet light has a short wavelength and red light has a long wavelength. All of the above is visible light, but beyond red light there is infrared light, and beyond violet light there is ultraviolet light. These two are invisible light. In addition to infrared light, there are radio waves and microwaves. These are harmless electromagnetic radiation.
The wavelength of electromagnetic radiation, if less than 100 nanometers, will form ionizing radiation. For example, X-rays, γ-rays and so on are ionizing radiation. Prolonged, large doses of ionizing radiation irradiation to the human body, will lead to cancerous cells in the human body. But the premise is a large dose, a long time. The short exposure time of CT will not cause any problem.