The German physicist Roentgen discovered X-rays in 1895, and the following year they were used in medicine and formed the new science of diagnostic radiology. Especially in the 1970s, the emergence of X-ray computed tomography (X-ray computed tomography, X-ray CT or CT), so that the medical diagnostics appeared a milestone development. X-ray fluoroscopy, X-ray photographs, as well as X-ray CT, this non-invasive examination, so that the doctor can be observed from the surface of the human body in-depth to the human body’s internal. Through this kind of imaging of the patient’s internal structure and organs, and through this to understand the human body’s anatomy and physiological function status and pathological changes of the examination has strongly promoted the development of clinical medicine, and has made great contributions to human health. Radiology and orthopedics, neurology, respiratory medicine and other interdependent relationship, some surgical experts say that radiology in a sense is an extension of their eyes, because radiological imaging for their preoperative diagnosis, the design of surgical programs and post-operative observation of the effect of the provision of a reliable basis. With the development of science and technology, radiology medicine from the past pure diagnostic medicine development into diagnosis and treatment of both comprehensive, marginal disciplines. 70’s the rapid emergence of interventional radiology (Interventional radiology), that is, under the monitoring of the image of the collection of specimens or the treatment of certain diseases, this integration of diagnostic and therapeutic features, changed the radiology department purely as an auxiliary diagnostic department of traditional medicine. This integration of diagnostic and therapeutic features has changed the traditional concept of radiology as an auxiliary diagnostic department. Interventional radiology, which permeates various disciplines, has become the preferred treatment method for many diseases such as middle and late stage cancer, vascular disease, heart disease, etc. due to its advantages of being minimally invasive, simple, safe, effective, with fewer complications and faster recovery. It has changed many traditional medical and surgical treatment modes and opened up new ways to solve many difficult clinical problems. Since its discovery, X-rays have brought great benefits to human health, but they have also caused harm to human beings. Today, medical exposure has become the largest man-made source of radiation exposure to the population (accounting for about 83% of the total dose of artificial radiation). It is our goal to correctly understand X-rays and to use them rationally and effectively to avoid harm and minimize the hazards. Radiation energy can be divided into two categories: particulate radiation and electromagnetic radiation. X-rays with very high frequency and huge energy, these high-energy photons are enough to ionize atoms and molecules, so they are called ionizing radiation. When the body is subjected to ionizing radiation, the biological effects of radiation are harmful, and the occurrence of biological effects of radiation is a very complex process: starting from the atomic level of excitation or ionization, and then cause molecular level damage (such as protein molecules, DNA strand breaks and enzyme destruction, etc.), and further affect the cellular level of the tissues and organs, and to the level of the overall damage. Tissues and organs sensitive to X-ray radiation include bone marrow, gonads, eye crystals, etc. Exposure above the threshold dose can cause hematopoietic hypoplasia, reattachment, temporary or permanent infertility, clouding of eye crystals, and cataracts. The sensitivity to X-rays is also related to the individual and age, with sensitivity decreasing from fetus, infancy, adolescence, youth to adulthood, and increasing in the elderly. Of greatest concern in radiation damage are gene mutations and chromosomal aberrations. If damage and mutations in the DNA of irradiated cells do not result in cell death, but rather in faulty repair and transmission of faulty information to progeny cells, the consequences of such cellular mutations are serious: somatic cell mutations may result in the formation of carcinomas, and mutations in germ cells may give rise to hereditary diseases. The National Cancer Institute speculates that 57 million CT exams could increase the number of future cancer cases by 29,000, and that too many chest CT exams increase the risk of breast and lung cancer in women. Given that there are pros and cons to medical X-ray imaging in one way or another, it is important for physicians and patients to use X-rays appropriately. Clinicians should always be aware that X-rays in medicine can be harmful and should weigh the pros and cons of requesting a radiology exam so that the benefits outweigh the possible harms and the exam is necessary and appropriate. Physicians should recognize that CT is not necessary if they can be photographic (a single chest CT scan is equivalent to the dose of 400 chest radiographs); they should not be reviewed if they can be done without a short-term review; and they should not be repeated if there is information on the test from an outside hospital and it meets the criteria. Although X-ray imaging (fluoroscopy, photographs and CT) can be harmful, patients should not be discouraged from using it, and when the doctor makes the right decision about X-ray imaging, patients should actively cooperate without excessive worry, because proper medical X-ray imaging is still relatively safe.