MRL in the clinic usually refers to Mrl, i.e. magnetic resonance imaging, abbreviated as MRI, magnetic resonance or nuclear magnetism, which uses a stronger external magnetic field and the nucleus of hydrogen atoms inside the human body to produce resonance under the action of specific radio frequency pulses, and then imaged by specialized equipment. It is a commonly used clinical examination as an aid to diagnosis. By scanning the patient’s affected area and obtaining imaging data of the affected area, the presence, extent or severity of the lesion is determined. MRI is a safe and reliable high-tech inspection device with very fine, clear and lifelike images. It has a wide range of clinical indications, and although it is the preferred examination method for lesions in the cranial brain, spinal cord, bone and joint cartilage, and synovial ligaments, it still has certain limitations, such as not being as sensitive as cranial CT for fresh bleeding in the head, but diagnosing early cerebral infarction earlier than spiral CT.