Clinical validity of a new T2-weighted MRI-based grading system for lumbar disc degeneration

Objective: To assess the clinical validity of a new grading system based on T2-weighted magnetic resonance imaging (MRI) for lumbar disc degeneration Study Design: Retrospective study Overview of the Literature: Various MRI classification criteria have been widely used for evaluation of intervertebral disc pathology. However, there is still considerable controversy regarding the MRI factors that allow accurate diagnosis. Materials and Methods: Data were collected from 570 lumbar discs in 114 patients and evaluated. The new grading system based on T2-weighted MRI was developed for lumbar disc degeneration, and its clinical validity was assessed. Symptoms were categorized according to the Japanese Orthopaedic Association's low back pain score (JOA score; 15-point-method). Moreover, the intraobserver reproducibility and interobserver reliability of the new grading system were compared with those obtained by using the commonly-used Schneiderman's criteria. Results: The shape of nucleus pulposus and signal intensity could be evaluated in the new grading system. Leg symptoms and walking ability graded by JOA score correlated with a new grading system (p < 0.05). The rate of intraobserver reproducibility of the new grading system showed a little higher agreement (85.0%) compared with Schneiderman's criteria (81.5%). The rate of interobserver reliability was similar. Conclusion: The new T2-weighted MRI grading system for disc degeneration was primarily useful for assessing leg symptoms and walking ability. Intraobserver reproducibility of the new grading system was higher than those of Schneiderman's criteria.