MRI is a type of magnetic resonance imaging, tomography, which utilizes the magnetic resonance phenomenon to obtain electromagnetic signals from the human body and reconstruct information about the human body. Technical characteristics of the magnetic resonance signal used for imaging, directly from the object itself, can be obtained in any direction of the tomographic image, three-dimensional body image, and even can get the spatial – spectral distribution of the four-dimensional image. Therefore magnetic resonance imaging belongs to a popular research direction in medical imaging. MRI is a physical phenomenon that has been applied to imaging diagnosis of various systems of the whole body. The effect is relatively good is the cranial brain, and its spinal cord, heart large blood vessels, joints and bones, soft tissues and pelvic cavity. There is no ionizing radiation damage to the human body when using it, and it is able to obtain native three-dimensional cross-sectional imaging without the need for reconstruction to obtain multi-directional images. Special attention should be paid to the presence of very strong magnetic fields in the MRI machine and the MRI examination room, and patients with pacemakers are prohibited from undergoing an MRI examination.