Carpal tunnel syndrome: diagnosis by means of median nerve elasticity--improved diagnostic accuracy of US with sonoelastography.
OBJECTIVE
To compare the elasticity of the median nerve (MN) between healthy volunteers and patients with carpal tunnel syndrome (CTS) and to evaluate the diagnostic utility of sonoelastographic measurements of the elasticity of the MN.


METHODS
This study was performed with institutional review board approval and written informed consent from all participants. Hands in 22 healthy volunteers and in 31 patients with symptomatic CTS were studied. The cross-sectional area (CSA) and the elasticity of the MN, which was measured as the acoustic coupler (AC)/MN strain ratio, were evaluated.


RESULTS
Both hands in 22 healthy volunteers (three men [mean age, 52.7 years; age range, 41-65 years]; 19 women [mean age, 62.2 years; age range, 40-88 years]) and 43 hands in 31 patients with symptomatic CTS (three men [mean age, 69.0 years; age range, 46-88 years]; 28 women [mean age, 61.2 years; age range, 39-92 years]) were studied. Both the AC/MN strain ratio and the CSA in the patients with CTS were significantly higher than those in the healthy volunteers (P < .001). The presence of CTS was predicted by means of AC/MN strain ratio and CSA cutoff values, respectively, of 4.3 and 11 mm(2), with areas under the receiver operating characteristic curves (AUCs) of 0.78 (95% confidence interval [CI]: 0.69, 0.88) and 0.85 (95% CI: 0.78, 0.93). A logistic model that combined the AC/MN strain ratio and the CSA improved diagnostic accuracy for CTS, with an AUC of 0.91 (95% CI: 0.85, 0.97; P < .001).


CONCLUSIONS
Sonoelastography provides significant improvement in the diagnostic accuracy of the ultrasonographic assessment of CTS.
From the Department of Diagnostic Radiology (H.M., M.K., G.M.F., W.R.J., A.S.K.), Department of Trauma Surgery and Sports Medicine (M.G., R.A.), and Department of Internal Medicine I, Clinical Immunology and Infectious Diseases (R.B.), Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria; Department of Orthopaedic Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan (H.M.); and Department of Radiology, Thomas Jefferson University, Philadelphia, Pa (E.J.H.).
Hideaki
H
Miyamoto
Ethan J
EJ
Halpern
Martin
M
Kastlunger
Markus
M
Gabl
Rohit
R
Arora
Rosa
R
Bellmann-Weiler
Gudrun M
GM
Feuchtner
Werner R
WR
Jaschke
Andrea S
AS
Klauser
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011237:Predictive Value of Tests