Diagnostic Value of Ultrasound and Shear Wave Elastography of Median Nerve in Carpal Tunnel Syndrome

Abstract Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy leading to work-related disability. Utility of high-resolution ultrasound (US) and shear wave elastography (SWE) for diagnosis with optimal diagnostic cutoffs in Indian cohorts remains underexplored. Primary objective was to determine diagnostic utility of elastography of median nerve between CTS patients and healthy volunteers. Secondary objective was to compare the ultrasonographic morphometry to Carpal Tunnel Syndrome-6 (CTS-6) score and nerve conduction study findings. In this prospective study, 40 patients with clinically suspected CTS (60 wrists) and 20 healthy volunteers (20 wrists) underwent CTS-6 scoring, electrodiagnostic evaluation, US morphometry, and SWE. Median nerve cross-sectional area (CSA), cross-sectional circumference, width-to-thickness ratio, and CSAprox/CSAdistal ratio, SWE stiffness (kPa), and velocity (m/s) were measured. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis. Mean CSA was significantly greater in CTS patients compared to controls (0.13 vs. 0.07 cm2, p < 0.001). SWE stiffness and velocity were markedly elevated in CTS (80–90 kPa; 4.5–5.0 m/s) relative to controls (< 40 kPa; 2.5–3.0 m/s, p < 0.001). ROC analysis demonstrated SWE stiffness had the highest diagnostic accuracy (area under the curve 0.97). At a threshold of 63 kPa, sensitivity was 93% and specificity 95%. Morphometric indices performed less well (CSA cutoff 0.085 cm2: 78% sensitivity, 70% specificity). SWE offers superior diagnostic accuracy compared with morphometric US parameters and approaches the performance of electrodiagnostic testing. Integrating SWE can be recommended for diagnosis of CTS.