Criteria for stratifying of nerve injuries on MRN and surgery based on Sunderland classification
| Class | MRN | Surgical |
|---|---|---|
| I | Qualitative: Homogeneous increased T2 signal of nerve with no change in caliber | Intact with no internal or external fibrosis, normal mobility and neuroarchitecture (visualize fascicles and Fanconi bands) |
| Quantitative: No changes | ||
| II | Qualitative: Homogeneous increased T2 signal of nerve and mild nerve thickening Perineural fibrosis | Intact with no internal fibrosis with external fibrosis, restricted mobility but neuroarchitecture intact (visualized fascicles and Fanconi bands once external scar removed) |
| Quantitative: <50% larger than contralateral /normal nerve | ||
| III | Qualitative: Homogeneous increased T2 signal of nerve and moderate to marked nerve thickening Perineural fibrosis | Intact with both internal and external fibrosis, restricted mobility and disturbance of neuroarchitecture (abnormal fascicle patterns and/or Fanconi bands not visible) |
| Quantitative: >50% larger than contralateral/normal nerve | ||
| IV | Qualitative: Heterogeneous increased T2 signal of nerve and focal enlargement in otherwise continuous nerve (neuroma in continuity) Perineural and intraneural fibrosis | Partial transected nerve, but some amount of distal nerve present with or without lateral neuroma |
| Quantitative: Focal swelling with heterogeneous T2 signal or fascicular disruption | ||
| V | Qualitative: Discontinuous nerve with end-bulb neuroma | Completely transected nerve with or without amputation (end-bulb) neuroma |
| Quantitative: Complete disruption with gap and end-bulb neuroma |