Utility of shear wave elastography and high-definition color for diagnosing carpal tunnel syndrome

Abstract

Objective: The diagnostic values of measuring median nerve (MN) stiffness and vascularity with shear wave elastography (SWE) and high-definition (HD) color were investigated in carpal tunnel syndrome (CTS).

Methods: Seventy patients (123 wrists) with CTS and thirty-five healthy volunteers (70 wrists) were enrolled. Based on nerve conduction studies (NCS), the patients were subdivided into NCS-negative, mild-to-moderate, and severe CTS groups. MN and abductor pollicis brevis (APB) SWE and MN HD color were performed on a longitudinal plane.

Results: The mild-to-moderate and severe CTS groups showed increased MN stiffness at the wrist and MN stiffness ratio (wrist-to forearm) compared with the control (p < 0.001). The NCS-negative CTS group showed increased MN stiffness at the wrist (p = 0.022) and MN stiffness ratio (p = 0.032) compared with the control. The severe CTS group showed increased MN stiffness at the wrist compared with the mild-to-moderate CTS group (p = 0.034). The cutoff-values in diagnosing NCS-confirmed CTS were 50.12 kPa for MN stiffness at the wrist, 1.91 for MN stiffness ratio, and grade 1 for HD color.

Conclusions: SWE and HD color are good supportive tools in diagnosing and assessing severity in CTS.

Significance: SWE and HD color demonstrated that MN in CTS was associated with increased stiffness and hypervascularity.

Keywords: Carpal tunnel syndrome; High-definition color; Median nerve; Shear wave elastography; Ultrasonography.