Table 1: The Pfirrmann score for disc degeneration.

GradeStructureDistinction of nucleus and anulusSignal intensityHeight of intervertebral disc

IHomogeneous, bright whiteClearHyperintense, isointense to cerebrospinal fluidNormal
IIInhomogeneous with or without horizontal bandsClearHyperintense, isointense to cerebrospinal fluidNormal
IIIInhomogeneous, grayUnclearIntermediateNormal to slightly decreased
IVInhomogeneous, gray to blackLostIntermediate to hypointenseNormal  to moderately decreased
VInhomogeneous, blackLostHypointenseCollapsed  disc space