When doing MRI, why do doctors let their families stay while doctors go out?

We usually go to the hospital, often encounter to do some testing, such as: X-ray, CT, MRI and so on. In the eyes of many people, X-ray, CT and MRI are all harmful tests. As a result, these tests are naturally rejected. Among them, nuclear magnetic resonance is the most misunderstood test item. If the patient’s condition is more serious, sometimes the doctor will let some medical staff or family members stay in the examination room to accompany the patient. At this time, the doctor often leaves the examination room, and then carries out MRI examination on the patient in the studio. As a result, some people think that it is irresponsible for doctors to do so, allowing their families and patients to suffer from radiation, but they left. In fact, such an idea is very ignorant. This is because MRI testing requires doctors to operate. If doctors do not operate in the studio, the machine will not be able to automatically complete the test. < / P > < p > secondly, doctors do not harm the family members of patients. In fact, there is an essential difference between MRI and X-ray and CT. MRI does not have ionizing radiation that can cause harm to human beings. What is the specific matter? < / P > < p > in order to understand this problem, we should start with understanding the nature of radiation. Radiation can’t be seen or touched, so many people naturally have a sense of fear. If radiation is harmful, then life may not appear, because radiation is everywhere and cannot be avoided. Scientists have found that: in the universe, all objects whose temperature is higher than absolute zero will have radiation. And according to the third law of Thermodynamics: absolute zero cannot be achieved. We can deduce that it is impossible for any object in the universe to reach absolute zero, because any object in the universe will have radiation. For example, our body temperature is between 36 and 37 degrees, which is definitely higher than absolute zero. Therefore, according to theory, the human body also has radiation. Then you may have to say, if the human body has radiation, why can’t we see it? < p > < p > objects radiate electromagnetic waves. The light we see everyday is actually a part of electromagnetic waves. The electromagnetic waves that we can see with the naked eye are called visible light bands, which only account for a small part of the whole family of electromagnetic waves. And there are many bands in the electromagnetic wave family that we can’t see with the naked eye. < / P > < p > the electromagnetic wave radiated by human body belongs to infrared wave band, which can not be seen by naked eyes. If we can detect it with infrared band detector, we can detect the electromagnetic wave radiated by human body. Therefore, human beings have radiation in fact. < / P > < p > knowing this, we will know that radiation is unavoidable. So we need to face up to radiation, not fear. Radiation is also divided into ionizing radiation and non ionizing radiation. Ionizing radiation is mainly particles and high-energy electromagnetic waves, while non ionizing radiation is mainly non-high-energy electromagnetic waves. Among them, ionizing radiation is harmful to human beings, but not ionizing radiation. At present, the experimental results show that it mainly has heating effect on human beings. The visible light in sunlight belongs to non ionizing radiation, and mobile phone belongs to non ionizing radiation, in which the radiation energy of mobile phone is far lower than that of sunlight. Although ionizing radiation is harmful to human body, but also depends on the dose. If a single exposure of 100msv radiation, mSv is the unit, it will increase the probability of cancer by 4.8%. If the single irradiation is lower than 100msv radiation, there is no clinical increase in the risk of cancer. We are familiar with CT and X-ray are ionizing radiation, so they are theoretically harmful. Why do they still use them? < / P > < p > chest X-ray: 0.2msv head CT: 2msv chest CT: 8msv abdominal CT: 10msv PET-CT: 30msv so, you can see these are far less than 100msv. However, generally speaking, if you are a reliable doctor, you will not be advised to do X-ray and CT when there is no need. < / P > < p > the principle of nuclear magnetic resonance is to change the state of atoms from high-energy level to low-energy state, and radio will be sent out in the whole process, which can map the parts of the human body that are examined. In fact, nuclear magnetic resonance testing belongs to non ionizing radiation, that is to say, it belongs to the radiation of sunlight and mobile phone. Its main impact on human beings is heating effect. Therefore, it does not harm human beings, nor does it harm the health of patients’ families. It is no problem for family members or medical staff to accompany them. However, there is one thing to pay attention to when using NMR. The magnetic field was used throughout the inspection. Therefore, it must be carried out in an enclosed space. If not, many metal parts will shift under the action of magnetic field, such as metal teeth or pacemaker. < / P > < p > What’s more, if you don’t close the door, you will even suck some metal objects out of the inspection room, and the detection equipment will be useless. That’s why doctors operate in the studio, knowing that some components of the computer are also metal. Therefore, the operating room must be separated from the testing room, so it is impossible for doctors to carry out tests in the room with patients. 20