Shear-wave elastography evaluation of thenar muscle in carpal tunnel syndrome.

Abstract

We aim to evaluate the shear wave velocity (SWV) of the thenar muscle as an adjunct diagnostic tool for carpal tunnel syndrome (CTS). Ninety-two wrists with CTS and 30 control wrists without CTS underwent ultrasonographic evaluation of thenar muscle and median nerve including shear-wave elastography. Cross sectional area (CSA) of medial nerve and SWV of thenar muscle and median nerve were evaluated. CTS patients were assessed for Boston CTS, Padua CTS, modified Hirani grading scores, and nerve conduction study (NCS). SWVs, CSA, and NCS parameters were compared between two groups. The SWVs of thenar muscle and median nerve (p < 0.001, respectively), and CSA of median nerve (p < 0.001) were more significantly greater in patients with CTS than in controls. The SWV of median nerve was moderately correlated with CSA of median nerve (r=0.35, p < 0.001) and modified Hirani CTS score (r=0.35, p < 0.001). The SWV of thenar muscle was inversely correlated with modified Hirani CTS score (r=-0.21, p=0.04). The SWV of thenar muscle and median nerve of CTS were significantly increased compared to that of control, and significantly negatively correlated with NCS parameters (modified Hirani CTS score). SWVs may be used as an adjunct diagnostic tool for CTS.