Preliminary evaluation of shear wave elastography for median nerve neuropathy

Abstract

Objective To explore the feasibility of real-time quantitative shear wave elastography (SWE) in median nerve (MN) lesions. Methods Seventy-three healthy volunteers (total 146 nerves) were included as control group (group A). The neuropathic group consisted of 85 patients (total 115 nerves), according their clinical symptoms and electrophysiological results. They were divided into two groups: diabetic peripheral neuropathy group (group B, 57 nerves) and carpal tunnel syndrome group (group C, 58 nerves). The real-time quantitative SWE embedded in Supersonic AixPlorer was used to detect the MN. The mean elasticity modulus of the MN at the wrist (WEmean), at the midpoint of the forearm (FEmean) and the mean elasticity modulus ratio of the MN and the musculus flexor digitorum superficialis in the same interest region at the midpoint of the forearm (FRatio) were calculated. Receiver-operating characteristic (ROC) curve was drawn to assess the diagnostic efficiency. Pearson rank correlation was used to analyze the correlation between the cross-sectional area (CSA) and WEmean of MN at the level of pisiform bone. Results There were significant differences of the elastic parameters between group C and A (P 0.05). The area under the curve(AUC) of elastic parameters indicated that WEmean and FEmean were higher than FRatio in diagnosis of carpal tunnel syndrome(AUC>0.8). No significant difference of diagnostic value was found between WEmean and FEmean(P>0.05). The CSA of MN positively correlated with WEmean (r=0.33, P<0.05). Conclusions SWE technology showed its feasibility in MN evaluation. It could be used to assess the stiffness of nerve neuropathy and may be a quantitative tool for clinical median neuropathy diagnostics. Key words: Ultrasonography; Median neuropathy; Shear wave elastography