Novel Application of the Pfirrmann Disc Degeneration Grading System to 9.4T MRI: Higher Reliability Compared to 3T MRI

Study Design. Reliability study. Objective. To evaluate the applicability and reliability of 9.4T magnetic resonance imaging (MRI) in the assessment of degenerative disc disease compared with 3T MRI. Summary of Background Data. MRI is a reliable indicator of biochemical changes in the intervertebral disc (IVD) including hydration status, proteoglycan content, and disc degeneration compared with anatomical and histological studies. High-field 9.4T MRI has been shown to provide superior resolution and anatomical detail. However, it has not been tested against current standard MRI techniques. Methods. Disc degeneration was initiated in 36 skeletally mature ewes 6 months prior to necropsy via validated surgical IVD injury models using either scalpel injury or drill-bit injury techniques at lumbar spine levels L2/3 and L3/4 with L1/2, L4/5, and L5/6 serving as control discs. All ex vivo IVDs were examined with 9.4T MRI and 3T MRI. All scans were analyzed using the Pfirrmann grading system by four independent observers. Intra- and interobserver reliability was assessed using kappa statistics and Spearman correlation. Results. Inter- and intraobserver agreement for 9.4T MRI was excellent, both at κ 0.91 (P 
Source: Spine - Category: Orthopaedics Tags: DIAGNOSTICS Source Type: research