The intervertebral disc consists of cartilage plate, annulus fibrosus and nucleus pulposus, with cartilage plate on the top and bottom, which is transparent cartilage covering the vertebral body, and the bone surface in the middle of the epiphyseal ring below. After puberty, various tissues of the human body appear degenerative changes, in which the changes in the intervertebral disc occur earlier, the main change is the nucleus pulposus dehydration, dehydration of the intervertebral disc loses its normal elasticity and tension, resulting in the annulus fibrosus is weak or rupture, the nucleus pulposus is protruding from the place, compression of the nerve root and produce signs of nerve root injury; can also be protruded backward from the center, compression of the cauda equina. If the annulus fibrosus ruptures completely, the broken nucleus pulposus enters the spinal canal, causing extensive cauda equina damage. Due to the heavy burden on the lower lumbar region and the many activities, herniation occurs mostly in the lumbar 4-5 and lumbar 5-sacral 1 intervertebral space. MRI manifestation: the disc height is reduced and the signal intensity is reduced in T2WI, which may or may not be accompanied by diffuse bulging of the disc or limited herniation, prolapse, or free, and the “vacuum sign” containing gas can be seen in the disc in severe degeneration. Another important change is endplate degeneration, which can be categorized into three types on MRI: Type 1: vascularization of the bone marrow with long T1 and long T2 signals; Type 2: chronic deposition of adipose tissue in the endplates and vertebral bodies with short T1 and slightly long T2 signals; and Type 3: sclerosis of the bone with long T1 and short T2 signals.