MR neurography of tibial and common peroneal nerves in patients with Guillain-Barre syndrome and electrophysiological correlation

Background The early and accurate evaluation of peripheral nerve injury in Guillain–Barre syndrome (GBS) patients is of great significance for clinical diagnosis and treatment. There has been recent interest in using Diffusion-weighted imaging with background suppression (DWIBS) to evaluate peripheral nerves and corresponding lesions, but has not been applied in GBS patients. Objective To explore the value of MR neurography in evaluating tibial nerve (TN) and common peroneal nerve (CPN) in GBS patients. Methods 36 GBS patients and 36 healthy volunteers were included in this prospective study. The cross-sectional areas (CSA) and signal-to-noise ratio (SNR) values of TN and CPN on T2-weighted images were calculated. Four-grade scoring system was used to score DWIBS images of TN and CPN. The CSA and SNR values, nerve scores on DWIBS were compared. Pearson correlation tests were used to assess the correlation between the CSA and SNR values, nerve scores and electrophysiology parameters of the GBS group. Results The interobserver agreement of measurements and nerve scored values was excellent. The mean CSA and SNR values of TN and CPN were significantly larger in patients than healthy controls (P<0.05). There were statistically significant differences in nerve scores between two groups (P < 0.01). The SNR values of TN correlated negatively with motor nerve conduction velocity (MCV) and motor nerve conduction amplitude (P < 0.01). The SNR values of CPN correlated negatively with MCV (P = 0.02). The nerve scores of TN and CPN were all positively correlated with MCV and motor nerve conduction amplitude (P < 0.01). Conclusions MR neurography showed larger CSA, higher SNR values of TN and CPN and unclear nerve on DWIBS. The SNR values and nerve scores on DWIBS have correlation with electrophysiological parameters. These findings suggest that MR neurography can be useful to assess the damage of TN and CPN in GBS patients.