Lumbar Spine: Reliability of MR Imaging Findings

Purpose: To characterize the inter- and intraobserver variability of qualitative, non–disk contour degenerative findings of the lumbar spine at magnetic resonance (MR) imaging. Materials and Methods: The case accrual method used to perform this institutional review board–approved, HIPAA-compliant retrospective study was the random selection of 111 interpretable MR examination cases of subjects from the Spine Patient Outcomes Research Trial. The subjects were aged 18–87 years (mean, 53 years ± 16 [standard deviation]). Four independent readers rated the cases according to defined criteria. A subsample of 40 MR examination cases was selected for reevaluation at least 1 month later. The following findings were assessed: spondylolisthesis, disk degeneration, marrow endplate abnormality (Modic changes), posterior anular hyperintense zone (HIZ), and facet arthropathy. Inter- and intraobserver agreement in rating the data was summarized by using weighted κ statistics. Results: Interobserver agreement was good (κ...