The radiation from a CT is high.
The radiation of CT is 20mSv, while the radiation of flying 10,000 kilometers by plane is 0.05mSv, so the radiation of doing a CT is 400 times that of flying 10,000 miles by plane.
Radiation is actually not so terrible, some misconceptions about radiation exaggerate the danger of radiation, in addition to the human body has the ability to self-repair, within a certain dose range, the body is able to self-repair, will be discharged out of the body of radiation. "People every moment to accept a variety of radiation from nature, such as the building materials of the house also has radiation, and people take the airplane at 10,000 meters high when the radiation absorbed is on the ground 10 times. The dose of ionizing radiation absorbed by the human body each year is under 100 millisieverts, which does not cause significant harm to the body."
Expanded:
Medical radiation is hazardous, and even though the hazard is so small that we can't even feel it, it's important to be exposed to it as little as possible.
The state has established three main principles for receiving medical radiation: justification of practice, optimization of radiation protection, and personal dose limits. To put it simply, if a patient's condition really requires it, no amount of medical radiation is too much; if it's not necessary, try not to be exposed.
In short, there is no radiation from ultrasound and magnetic **** vibration (MRI), and there is radiation from X-rays, CTs, and nuclear medicine, but the amount of radiation is not large, and the hazards are within manageable limits. Therefore, for the sake of your condition, you should openly accept the relevant examinations; however, if it is not necessary, please try to avoid exposure to medical radiation, because such radiation is still potentially harmful after all.
People's Daily Online - an X-ray examination is equivalent to flying 20,000 kilometers on a plane
Phoenix.com - the maximum amount of radiation from a CT may be several hundred times the amount of X-rays taken chest X-rays expert: CT a year don't more than twice