Role of magnetic resonance neurography in assessment of lumbosacral radiculo-plexopathy: correlation with electrophysiological studies

Abstract

BackgroundLumbosacral plexus is a collection of nerves that converge and diverge and finally merge into terminal nerves that innervate the pelvis and lower limbs. Lumbosacral plexopathy is a clinical disease characterized by motor and sensory abnormalities that can result from damage to the lumbosacral plexus by different types of insults. Electrophysiological studies are used to demonstrate the presence of lumbosacral radiculo-plexopathy, but it is restricted owing to deep position of nerves and regional differences in muscle nerve supply. High-resolution MR neurography can simply show the precise site, size, etiology, and type of the lumbosacral radiculo-plexopathy. The aim of this study was to assess the various diseases affecting the lumbosacral plexus with their 1.5-T MR neurography imaging findings and to correlate these findings with electrophysiological studies.ResultsFifty adult patients with clinical presentation of lumbosacral radiculo-plexopathy were included in this cross-sectional study. Based on clinical diagnosis, the sensitivity of electrophysiological studies in diagnosing lumbosacral radiculo-plexopathy was 80% and the sensitivity of MR neurography in diagnosing lumbosacral radiculo-plexopathy was 90%. While based on electrophysiological studies, the sensitivity of MR neurography in diagnosing lumbosacral radiculo-plexopathy was 97.5% and the specificity was 75.86%. There was a high statistically significant relation between the side affected in electrophysiological studies and the side affected in MR neurography and between the stage of the lesion in the electrophysiological studies and in MR neurography among patients (p ≤ 0.001, p ≤ 0.001) , respectively.ConclusionsMR neurography of the lumbosacral plexus is a helpful non-invasive approach for the assessment of patients with inconclusive lumbar spine MR imaging because of its ability for diagnosis of neuromuscular lesions and determining their causes. Electrophysiological studies assess the nerve function and MR neurography assesses the nerve anatomy, and therefore, the correlation between electrophysiological studies and MR neurography are complementary for detection of lumbosacral radiculo-plexopathy.