Magnetic resonance examination generally does not cause radiation to the human body, but the use of magnetic resonance examination should be contraindicated for the installation of stents, pacemakers or metal foreign objects in the body. The magnetic field used in magnetic resonance examination is an applied magnetic field, which has no radiation effect on the human body and will not cause serious harm to the body. When the human body undergoes magnetic resonance examination, metal devices of the body should be removed in order to avoid electromagnetic reaction during the examination. As the magnetic resonance examination is carried out in a relatively confined space, the space is relatively small and the examination time will be relatively long, therefore, for patients with claustrophobia, the examination process will cause a certain amount of mental stimulation, resulting in a sense of fear, and the appearance of rapid heartbeat. In addition, when doing magnetic resonance examination, should be well prepared psychologically, for the body to install stents or pacemakers, as well as pregnant women and other people should be cautious to use magnetic resonance examination.