The Association Between Magnetic Resonance Imaging Disc Pathology and Provocative Discography at the Lumbar Level.

OBJECTIVE: The objective of this study was to show that degenerative lumbar magnetic resonance imaging findings variably increase discography pain by level. METHODS: Lumbar discography and magnetic resonance imaging of 736 patients were retrospectively reviewed. Univariate/multivariate logistic regressions calculated the odds ratio (OR) (95% confidence interval, P < 0.05). RESULTS: L3-4 multivariate regression OR for a degenerative disc is 9.9; for bulge, 10.9; for annular tear, 38.9; for herniation, 51.5; and for degenerative facet, 2.158. Endplate changes were not significant. L4-5 OR for a degenerative disc is 4.52; for bulge, 13.74, for tear, 19.13; for herniation, 28.65; for endplate edema, 3.47; and fatty change, 3.84. Degenerative facet ORs were not significant. L5-S1 OR for a degenerative disc is 6.86; for bulge, 5.65; for tear, 40.56; and for herniation, 77.98. Endplate changes and degenerative facet OR's were not significant. CONCLUSIONS: Advancing degeneration increases pain at L5-S1 followed by L3-4. Endplate signal is significant only at L4-5.

Positive Predictive Values of Lumbar Spine Magnetic Resonance Imaging Findings for Provocative Discography.

PURPOSE: The purpose of this study was to calculate the positive predictive value (PPV) of lumbar spine magnetic resonance imaging (MRI) findings for a painful disc using provocative discography. MATERIALS AND METHODS: Lumbar spine discography records and prediscography MRIs of 736 patients (2457 discs) who underwent discography for diagnostic purposes from 2003 to 2007 were retrospectively reviewed in an Institutional Review Board-exempt and Health Insurance Portability and Accountability Act-compliant protocol. Each level was identified as having high-intensity zone (HIZ) disc, disc protrusion, disc extrusion, or combination (any herniation type), disc bulge, disc degeneration, and spondylolisthesis. Statistical analysis used a 2 × 2 contingency table of significant discography results for each of the MRI variables to calculate P value and PPV with a confidence interval from a binomial distribution. RESULTS: An HIZ disc has a PPV of 0.71 (0.65-0.76, P = 4.31E - 44) for a provocative discography. A disc protrusion has a PPV of 0.79 (0.73-0.83, P = 2.68E - 53). A disc extrusion has a PPV of 0.93 (0.79-0.98, P = 1.34E - 14), a bulge of 0.43 (0.37-0.48, P = 0.002), and a degenerative disc of 0.32 (0.28-0.35, P = 0.08), and spondylolisthesis has a PPV of 0.67 (0.59-0.73, P = 1.70E - 20). A herniation of either type (extrusion or protrusion) has a PPV of 0.80 (0.75-0.84, P = 5.86E - 69). CONCLUSIONS: Disc herniations and HIZ discs have high predictive value in identifying a pain generator. An extruded disc herniation has the highest PPV for discogenic pain.

Modic changes on MR images as studied with provocative diskography: clinical relevance--a retrospective study of 2457 disks.

PURPOSE: To assess the value of vertebral body endplate signal intensity (Modic) changes on magnetic resonance (MR) images in predicting a painful disk, with provocative diskography as the reference standard. MATERIALS AND METHODS: Lumbar spine diskograms and prediskogram MR images of 736 patients (2457 disks) were retrospectively reviewed as part of an institutional review board-approved HIPAA-compliant protocol. Each disk was assigned a Modic subtype: type 0, normal; type 1, nonfatty high signal intensity; type 2, fatty; and type 3, sclerosis. Statistical analysis involved use of a 2 x 2 contingency table of diskogram results for each of the subtypes. The subtype sensitivity, specificity, positive predictive value (PPV), negative predictive value, and confidence intervals (CIs) were calculated. Similar analyses of other MR variables (such as disk herniation, high signal intensity zone, and spondylolisthesis) and type 1 signal intensity changes also were performed. RESULTS: Type 1 changes (n = 155) had a high PPV (0.81; 95% CI: 0.74, 0.87) for a provocative diskogram. Type 2 changes (n = 126) had a lower PPV (0.64; 95% CI: 0.55, 0.72) for a positive diskogram. Type 3 changes (n = 21) had a PPV (0.57; 95% CI: 0.34, 0.78) that was not significant for a positive diskogram. The PPV of an endplate with a type 1 change (hereafter, type 1 endplate) for a tear in the annulus fibrosis of the disk was also insignificant (0.14; 95% CI: 0.09, 0.20). A similar analysis between a type 1 endplate and the presence of a disk herniation (PPV, 0.26; 95% CI: 0.19, 0.34) and between a type 1 endplate and vertebral body spondylolisthesis (PPV, 0.28; 95% CI: 0.20, 0.35) were significant. CONCLUSION: Type 1 signal intensity changes on MR images have a high positive predictive value in the identification of a pain generator.