Original Research

Diagnostic Potential of High-Resolution Ultrasound of Median Nerve in Assessing the Severity of Carpal Tunnel Syndrome

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Abstract

Background: Carpal tunnel syndrome (CTS) is the most common peripheral compressive neuropathy diagnosed by a combination of clinical and nerve conduction studies (NCS). NCS is used to classify the severity of CTS, which forms the basis of its treatment. NCS is, however, a time-consuming, relatively expensive, and painful procedure that may not be available at all facilities. In comparison, high-resolution ultrasound (HRUS) offers several advantages — it is a painless, quick, easily accessible, and relatively inexpensive procedure. The purpose of this study is to evaluate the diagnostic potential of HRUS for grading the severity of carpal tunnel syndrome.

Methods and materials: This is a prospective descriptive study conducted at the Department of Radiology and Imaging at Nizam’s Institute of Medical Sciences. It includes 42 cases of CTS that were diagnosed and classified using both clinical assessment and NCS. In this study, we measured 11 HRUS gray-scale and color Doppler parameters of the median nerve and compared them with the NCS classification of the severity of CTS.

Results: Of 42 total diagnosed cases, 27 were classified as non-severe, while 15 cases were classified as severe cases of carpal tunnel syndrome based on NCS. The cross-sectional area (CSA) of the median nerve at the inlet, outlet, wrist-forearm ratio, wrist-forearm difference, vascularity score, and flattening ratio at the outlet were statistically significant predictors of severity. The CSA at the outlet was the best predictor of the severity of CTS (AUC = 0.811). Using a cut-off of 11 mm², the CSA at the outlet had a sensitivity of 40% and a specificity of 94.5% for the diagnosis of severe CTS. 

Conclusion: High-resolution ultrasound is a well-established modality for diagnosing carpal tunnel syndrome. HRUS parameters can also be utilized to grade the severity of CTS, which can be crucial for clinicians when selecting appropriate therapeutic interventions.

Keywords: carpal tunnel syndrome, high-resolution ultrasound, median nerve, diagnostic potential, severity assessment, nerve entrapment, cross-sectional area, nerve compression, carpal tunnel diagnosis, ultrasonographic assessment, wrist evaluation

How to Cite:

Thirumal, P Narayanan R, Chakravarty P, Yareeda S, Ravula P. Diagnostic potential of high-resolution ultrasound of median nerve in assessing the severity of carpal tunnel syndrome. J Glob Radiol. 2025;10(1):752.

Rights:

Copyright © 2025 Thirumal, Narayanan, Chakravarty, Yareeda, Ravula. This open access article is distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. (https://creativecommons.org/licenses/by/4.0/)