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 |
|
clear | hyperintense, isointese to cerebrospinal fluid | normal |
Grade II |
|
clear | hyperintense, isointese to cerebrospinal fluid | normal |
Grade III |
|
unclear | intermediate | normal to slightly decreased |
Grade IV |
|
lost | intermediate to hypointense | normal to moderately decreased |
Grade V |
|
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.