CT examinations and X-rays are basically the same. The difference is that X-rays take a flat image of the body, so the organs in the body will show the overlapping state before and after; while CT takes a tomographic approach, just like slicing bread into thin slices, and takes different pictures of the body parts being examined from different points, thus solving part of the overlapping problem. Generally speaking, diseases such as fractures can be seen clearly with X-rays, but CT is needed for lesions involving more complex structures such as intracranial tumors and liver tumors. Medical X-rays and CT examinations are currently the largest source of man-made radiation to which people may be exposed, and this radiation can penetrate cells, destroy DNA, and even induce certain cancer cells. Research by John Goffman, an internationally renowned radiologist, has found that X-rays can damage the internal structure of cells and produce lifelong damage to genetic molecules that are difficult to repair: of the 180,000 patients diagnosed with breast cancer in the United States each year, about 2/3 have a cause related to medical X-rays. Studies have also shown that X-rays destroy red blood cells and may induce blood disorders such as leukemia. Professor Burlington de Gonzalez of Oxford University in England said, “In men, the disease with the highest risk associated with X-rays is bladder cancer, partly because many different kinds of X-rays irradiate the bladder. And women have a higher risk of lung and colon cancer.” Self-precautionary safety distance – two meters away Patients who do not need special escort, family members do not need to go with them to the examination, so that exposure to radiation is completely unnecessary. However, it is not necessary to be afraid to enter the radiology department of the hospital for this reason. When taking a chest X-ray, the exposure rate in the examination area is about 160 mSv/h, and 80 mSv/h two meters away, which is about 1/2000 of the center point, and the chance of cancer is about one in a million; while the radiation 6 meters away from the center point is 1.5 mSv/h, which is about one in five million of the center point, and the chance of cancer is negligible. Vulnerable people – pregnant women and newborns Although X-rays and CT examinations during pregnancy do not absolutely lead to fetal malformations, it is recommended that pregnant women should avoid such examinations, especially those in the first trimester of pregnancy. Because this is a critical period for the formation of important fetal organs, X-rays may cause mutations in these undeveloped cells and tissues and increase the incidence of congenital malformations in the fetus. Studies have also shown that if a newborn has a CT scan due to head injury, it will have an effect on later learning ability and logical reasoning ability, but not on spatial recognition ability. Sensitive parts – gonads The cells in various parts of the body react differently to X-rays, with the gonads being the most sensitive. Foreign hospitals have done a better job of covering the gonads with lead sleeves or other protection when doing X-rays or CT exams of the lower abdomen to increase the insurance factor. But most hospitals in China do not have such protection. Eat more kelp It may be useful to eat more iodine-containing things like kelp, which can absorb some of the radiation.