Discogenic Lumbar Pain: Correlation between Magnetic Resonance Imaging and Discography

Shim, Jae Chol; Kim, Dong Won; Jeon, Jeong Woo

Abstract

BACKGROUND: Although numerous previous studies on the subject have been performed, the correlations between various pathologic findings on magnetic resonance imaging and pain reproduction by provoked discography have not been fully explained. A higher sensitivity and positive predictive value (PPV) of the high intensity zone (HIZ) for predicting concordant pain was reported. Moreover, although the apparent validity of this sign has been corroborated by some investigators, it has been questioned by others. The validity of this sign awaits confirmation. The various pathologic parameters seen on magnetic resonance imaging (MRI) in patients with discogenic lumbar pain was assessed and correlated with observations on discography.
METHODS
There were 18 patients enrolled, ranging in age from 28 to 64 years with an average age of 48.8 +/- 10.2 (mean +/- SD) years. Five men (28%) and thirteen women (72%) participated in the study. All patients underwent provocation discography by a standard technique, as mentioned previously. The lumbar discs examined were L3-L4;(2), L4-L5;(14) and L5-S1;(10). The relationship between discogenic lumbar pain and disc morphology was investigated by using MRI and provocation discography.
RESULTS
Of the 26 discs being studied, 16 proved to be concordantly painful at discography relative to clinical back, buttock, hip, groin, and proximal leg pain complaints. Fourteen of the 16 painful and concordant pain discs exhibit grade 2, 3 with annular tears, and four with free leakage of contrast into the epidural space. Using chi-square analysis, we observed a significant correlation (P < 0.05) between the annular disruption grade and the provoked pain response. We were not able to demonstrate that the HIZ was associated with any particular grade of disc disruption. Similarly, there was no significant correlation (P > 0.05) between a concordant pain response and the presence of an HIZ regardless of the level and grade of disc disruption.
CONCLUSIONS
The presence or lack of the HIZ does not exclude the disc as a source of pain and should not replace provocation discography as a means of evaluating low back pain with or without sciatica.