Pfirrmann graded the degree of lumbar disc degeneration by T2-weighted images of MR: Grade A: the structure of the disc is homogeneous with white high signal and its disc height is normal. grade B: the structure of the disc is heterogeneous with white high signal; the distinction between the fibrous ring and the nucleus pulposus is relatively obvious, with or without horizontal gray bands; grade C: the structure of the disc is heterogeneous with grayish white signal intensity in the middle signal intensity; the distinction between the fibrous annulus and the nucleus pulposus is not obvious, and the height of the disc is normal or slightly decreased; Grade D: the signal of the disc structure is heterogeneous with black low signal; the distinction between the nucleus pulposus and the fibrous annulus disappears, and the height of the disc is normal or moderately decreased; Grade E: the signal of the disc structure is heterogeneous with black low signal; the distinction between the nucleus pulposus and the fibrous annulus disappears, and there is collapse of the intervertebral space. The Pfirrman grading, as a 5-level grading system, is not sufficiently detailed for grading disc degeneration, and although it can be well applied to grading disc degeneration in young people, when we used it to grade disc degeneration in the elderly, we found that about 87% of the degenerated discs were difficult to determine as to whether it belonged to grade C or grade D. In elderly patients, the use of this classification also failed to clarify the relationship between disc degeneration and other factors. To overcome these problems, James designed the Modified Pfirrmann Classification, which expanded the original classification from 5 to 8 measures, subdivided the original D grade into 2 grades (i.e., modified grades 3 and 4), and subdivided the original D grade into 3 grades (i.e., modified grades 5, 6, and 7). Modified Pfirrmann grading system: grade 1, the signal of the nucleus pulposus and inner fibrous ring is mildly uniform bright white high signal, comparable to the signal of cerebrospinal fluid, the signal difference between the inner and outer posterior fibrous ring is obvious, and the disc height is normal; grade 2, the signal of the nucleus pulposus and inner fibrous ring is high signal (higher than the presacral fat and lower than the cerebrospinal fluid) or there is a horizontal fissure in the nucleus pulposus, and the signal difference between the inner and outer posterior fibrous ring is obvious. The disc height is normal; grade 3, the nucleus pulposus and the inner annulus fibrosus have high signal (lower than the presacral fat), the difference in the signal between the inner and outer posterior annulus fibrosus is obvious, and the disc height is normal; grade 4, the nucleus pulposus and the inner annulus fibrosus have moderate high signal (slightly higher than the outer annulus fibrosus), the difference in the signal between the inner and outer posterior annulus fibrosus is not obvious, and the disc height is normal; grade 5, the nucleus pulposus and the inner annulus fibrosus have low high signal (equal to the signal of the outer annulus fibrosus), and the disc height is normal. (equal to that of the outer annulus), insignificant difference between the medial and lateral signals of the posterior annulus, normal disc height; grade 6: low-high signal in the nucleus pulposus and inner annulus, insignificant difference between the medial and lateral signals of the posterior annulus, <30% reduction in disc height; < span="">grade 7, low-high signal in the nucleus pulposus and inner annulus, insignificant difference between the medial and lateral signals of the posterior annulus, 30%-60% reduction in disc At level 8, the nucleus pulposus and the inner annulus fibrosus show low-high signal, the difference between the medial and lateral signals of the posterior annulus fibrosus is not obvious, and the disc height is reduced by >60%.