Intervertebral disc degeneration in lumbar spine - MRI classification by Pfirrmann et al.

The Pfirrmann classification was developed in 2001 and was based on previous systems. It was validated on 60 MRI examinations of the lumbar spine assessed by three independent observers. The imaging protocol included sagittal T1 weighted spin-echo, T2 weighted fast spin echo (FSE) in sagittal and axial plane.

Grade Structure Distinction of nucleus pulposus and anulus fibrosus Signal intensity on T2 weighted images Height of intervertebral disc
Grade I
  • homogeneous
  • bright white
clear hyperintense, isointese to cerebrospinal fluid normal
Grade II
  • inhomogeneous
  • horizontal bands may be present
clear hyperintense, isointese to cerebrospinal fluid normal
Grade III
  • inhomogeneous
  • gray
unclear intermediate normal to slightly decreased
Grade IV
  • inhomogeneous
  • gray to black
lost intermediate to hypointense normal to moderately decreased
Grade V
  • inhomogeneous
  • black
lost hypointense collapsed disc space


1. Pfirrmann CW, Metzdorf A, Zanetti M, Hodler J, Boos N. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine. 2001 Sep 1;26(17):1873–8.