Grade | Structure | Distinction of Nucleus Pulposus and Annulus Fibrosus | Signal Intensity | Height of Intervertebral Disk |
---|---|---|---|---|
I | Homogeneous, bright white | Clear | Hyperintense | Normal |
II | Inhomogeneous with or without horizontal bands | Clear | Hyperintense | Normal |
III | Inhomogeneous, gray | Unclear | Intermediate | Normal-to-slight decrease |
IV | Inhomogeneous, gray to black | Lost | Intermediate to hypointense | Normal-to-moderate decrease |
V | Inhomogeneous, black | Lost | Hypointense | Collapsed disk space |