Gadolinium Diethylenetriaminepentaacetic Acid Enhancement in Magnetic Resonance Imaging in Relation to Symptoms and Signs among Sciatic Patients

Abstract

A cross-sectional descriptive study. Gadolinium enhancement in lumbar magnetic resonance imaging is not used routinely. The current study explored the possible intercorrelations of enhancement patterns with clinical symptoms and signs. Rim enhancement has been reported to occur in the periphery of disc herniations, and it is thought to represent neovascularization. To the authors' knowledge, the significance of the enhancement in relation to clinical symptoms has not been studied. Magnetic resonance imaging of the lumbar spine with intravenous gadolinium diethylenetriaminepentaacetic acid was performed in each patient. Various contrast enhancement parameters and volume of herniation were evaluated, and their correlations with clinical signs and symptoms (straight leg raising, motor defect, Achilles reflex, leg and back pain, disability) were analyzed. The extent of rim enhancement correlated highly significantly with the degree of disc displacement, being most pronounced in the case of sequesters. The duration of sciatic symptoms correlated negatively with enhancement. The clinical symptoms did not correlate significantly with the different enhancement parameters or disc herniation volume. Straight leg raising correlated only slightly with the extent of rim enhancement (P = 0.04) when bulges were excluded. Achilles reflex abnormality correlated significantly with all enhancement parameters for lesions at L5-S1. In the final stepwise logistic regression model, contrast enhancement extent correlated most significantly with abnormal Achilles reflex (P = 0.0002). Although rim enhancement of disc herniation is thought to represent a beneficial phagocytotic phenomenon, it may also have a harmful effect on the adjacent nerve root.