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World J Radiol. Mar 28, 2016; 8(3): 281-287
Published online Mar 28, 2016. doi: 10.4329/wjr.v8.i3.281
Grey-scale sonography and sonoelastography for diagnosing carpal tunnel syndrome
Hideaki Miyamoto, Yutaka Morizaki, Takahiro Kashiyama, Sakae Tanaka
Hideaki Miyamoto, Yutaka Morizaki, Takahiro Kashiyama, Sakae Tanaka, Department of Orthopaedic Surgery, Graduate School of Medicine, the University of Tokyo, Tokyo 113-8655, Japan
Author contributions: All authors contributed equally to this work; wrote and reviewed the paper.
Conflict-of-interest statement: There is no conflict of interest associated with any of the senior author or other coauthors contributed their efforts in this manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hideaki Miyamoto, MD, Department of Orthopaedic Surgery, Graduate School of Medicine, the University of Tokyo, 7 Chome-3-1 Hongo, Bunkyo, Tokyo 113-8655, Japan. s70842000@yahoo.co.jp
Telephone: +81-3-38155411 Fax: +81-3-38184082
Received: August 27, 2015
Peer-review started: August 31, 2015
First decision: November 24, 2015
Revised: December 6, 2015
Accepted: January 5, 2016
Article in press: January 7, 2016
Published online: March 28, 2016
Abstract

Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy of the median nerve at wrist level, and is thought to be caused by compression of the median nerve in the carpal tunnel. There is no standard quantitative reference for the diagnosis of CTS. Grey-scale sonography and sonoelastography (SEL) have been used as diagnostic tools. The most commonly agreed findings in grey-scale sonography for the diagnosis of CTS is enlargement of the median nerve cross-sectional area (CSA). Several authors have assessed additional parameters. “Delta CSA” is the difference between the proximal median nerve CSA at the pronator quadratus and the maximal CSA within the carpal tunnel. The “CSA ratio” is the ratio of CSA in the carpal tunnel to the CSA at the mid forearm. These additional parameters showed better diagnostic accuracy than CSA measurement alone. Recently, a number of studies have investigated the elasticity of the median nerve using SEL, and have shown that this also has diagnostic value, as it was significantly stiffer in CTS patients compared to healthy volunteers. In this review, we summarize the usefulness of grey-scale sonography and SEL in diagnosing CTS.

Keywords: Carpal tunnel syndrome, Cross-sectional area, Gray-scale sonography, Diagnosis, Median nerve, Sonoelastography, Elasticity

Core tip: The diagnostic value of grey-scale sonography and sonoelastography in carpal tunnel syndrome (CTS) is reviewed. Sonography can potentially allow a noninvasive screening, and could therefore be a preferable first-line approach to detect pathological changes of the intracarpal tunnel contents. This review summarizes the current knowledge of sonographic findings as a diagnostic tool in CTS.