In the evening of November 8, 1895, the German scientist Röntgen discovered a new, as yet unknown, type of ray and named it X-rays. In addition, he discovered that X-rays could also penetrate muscles to show the outline of bones. On December 28, 1895, Röntgen presented a paper on X-rays, “A New Ray – Preliminary Report,” to the Würzburg Institute of Physical Medicine. X-rays were used for medical examinations from the moment they were discovered. Today, with the rapid development of computer technology and radiation detector devices, X-ray imaging equipment is changing rapidly. Computed tomography (CT), computerized radiography (CR), direct digital radiography (DR), digital subtraction (DSA) interventional procedures and examinations, etc. have all become effective tools for clinical diagnosis and treatment that doctors cannot do without. Just like medication has side effects, the cells of the tissues and organs that are exposed to X-rays will also be damaged to some extent when receiving X-rays, but the damage is not immediately self-perceived. If the damage is mild, the likelihood of disease is minimal; if the radiation damage is severe, it can lead to the development of lethal cancers or genetic diseases. It has been proven that any living creature exposed to large doses of X-rays for long periods of time will eventually die. Various tissues and organs in the human body have different levels of sensitivity to radiation damage, and their sensitivity in descending order is as follows: embryo, gonad, breast, eye crystal, thyroid, liver, kidney, brain, and muscle. The International Commission on Radiation Protection (ICRP) has confirmed that radiation causes cancer and hereditary diseases in a linear dose without a threshold, which means that the more you are exposed, the greater the possibility of developing lethal cancer and hereditary diseases. ICRP proposes that radiation protection should follow three principles: justification of radiation use, optimization of protection and individual dose limits. China has adopted ICRP’s recommendations and a series of radiation protection regulations and standards have been formulated by the competent authorities to protect the radiation health safety of professionals, examinees and the public. The Ministry of Health of the People’s Republic of China issued the “National Measures for the Administration of Health Protection of Radiation Work” on January 3, 2002. It is clearly stipulated that “when diagnosing and treating patients and examinees (with radiation rays), the irradiated dose should be strictly controlled in accordance with the operating procedures, and the sensitive organs and tissues in the vicinity of the irradiation should be shielded and protected. Medical irradiation of pregnant women and children should be informed of the health effects.” The Ministry of Health also specifies in the Safety Operational Requirements for Medical X-ray Diagnostic Protection that appropriate shielding protection should be taken for sensitive parts of the body and tissues (e.g., gonads, thyroid, breast, etc.). Film and fluoroscopy are the most common and basic hard image examination means. The more naked the patient’s upper body is, the better, so as not to block the lesions with underwear buttons, bra hooks, necklaces, etc. When examining infants and children, the most difficult part is to fix the infant’s body position. Parents should not let the child cry and not allow the bundle to be fixed, otherwise your baby will be unnecessarily exposed to the whole body, and you will have to accompany to receive an X-ray injury. Non-examined parts, especially radiation-sensitive organs, should be kept as far away from the irradiation field as possible. For example, when taking upper (hand) and lower limb (foot) films, straighten the arms and legs, and keep the thyroid, breast and gonads away from the irradiation field. These are all things that the patient should actively cooperate with. When fluoroscopy you can doctor try to use pulsed bursts of light, so that the doctor naturally knows that you know the protection and will be more standard in the operation. The essence of CT is also the use of X-ray imaging, CT scan damage to the human body is more than 100 times higher than the film, do a CT whole body scan physical examination, will increase the risk of radiation cancer of the subject by about 8%. But few people ask for a full body scan at one time. If you are having a head CT scan you can ask the doctor to cover your neck (thyroid) to your mid-thighs (gonads) with a protective suit. It is also a good idea to keep your eyes closed. This is the easiest and most effective way to protect yourself. In the hospital if you are asked for mammography because of breast disease you can refuse. As of the end of 2004, no authority in any economically developed country has approved computerized radiography (CR) mammography for clinical diagnosis, much less for breast cancer screening. This is because the preferred test in hospitals is ultrasonography. As common sense, you should know that ultrasound and MRI are not damaging to the body in any way. At least not as far as science has discovered. Radiologists have the obligation to tell their patients, and patients have the right to know, the pros and cons of X-ray examinations, and whether there are alternatives, and to obtain the patient’s consent before billing for the examinations, especially for pregnant women, infant and young children patients, and to be more cautious. In general, if a pregnant woman receives 5 Gray (a unit) of X-ray burst, equivalent to 20 abdominal X-rays or 2 pelvic computed tomography, the chance of future fetal director will increase by 40% with such dose. But in practice, almost no hospitals do this. Patients should also refuse all unwarranted x-ray examinations. In conclusion, the use of X-rays for medical examinations should be legal, scientific and regulated. Radiation carcinogenesis is a random event, and the risk of carcinogenesis is a statistical result of a large number of population incidence events. With scientific and standardized use, the possibility of a patient causing cancer from one chest X-ray is only 1 in 100,000 or even lower, so patients should not talk about radiation.