Nuclear magnetic resonance (NMR) is usually non-radioactive. Nuclear magnetic resonance (NMR), also known as nuclear magnetic resonance (NMR), usually utilizes a large number of hydrogen nuclei in the human body, and under the action of a magnetic field, imaging, and through a computer can be processed from the NMR images, so NMR does not have a radiation effect, and there is no radiation level of the size of the situation. It is not the same as CT, X-ray, etc., which are usually scanned by X-rays, and therefore will cause some radiation to the human body. MRI does not produce rays, so it is relatively safe for people with sensitive bodies, such as pregnant women, infants and young children. In addition, if the patient is placed in the body of metal objects and other conditions, it is not recommended to carry out magnetic nuclear resonance examination, the patient should be under the guidance of the doctor in conjunction with their own condition to determine whether it is appropriate to do the MRI examination.