Semin Musculoskelet Radiol 2010; 14(5): 487-500
DOI: 10.1055/s-0030-1268069
© Thieme Medical Publishers

Entrapment Neuropathies II: Carpal Tunnel Syndrome

Andrea S. Klauser1 , Ralph Faschingbauer1 , Thomas Bauer3 , Marius C. Wick1 , Markus Gabl2 , Rohit Arora2 , Anne Cotten4 , Carlo Martinoli5 , Werner R. Jaschke1
  • 1Department of Diagnostic Radiology, Medical University Innsbruck, Innsbruck, Austria
  • 2Department of Trauma Surgery and Sports Medicine, Medical University Innsbruck, Innsbruck, Austria
  • 3Department of Plastic Surgery, Medical University Innsbruck, Innsbruck, Austria
  • 4Service de Radiologie et Imagerie Musculosquelettique, centre de consultation et d'imagerie de l'Appareil Locomoteur, Lille, France
  • 5Department of Radiology–DISC, University of Genoa, Genoa, Italy
Further Information

Publication History

Publication Date:
11 November 2010 (online)


Diagnostic tests in patients complaining of carpal tunnel syndrome (CTS) are based on physical examination, electrodiagnostic tests (EDTs), and diagnostic imaging. Timely diagnosis helps prevent permanent nerve damage and its sequelae in terms of functional impairment. Imaging provides additional information to that obtained from clinical tests and EDTs. By allowing direct visualization of the compressed median nerve (MN), ultrasound (US) and magnetic resonance imaging can depict the causes for secondary CTS and describe anatomical variants, such as a bifid MN or a persistent median artery of the forearm, as well as space-occupying lesions including tenosynovitis and ganglion cysts. In addition, diagnostic imaging is of value for postoperative patients presenting with persistent symptoms. Finally, US is able to add information for EDT-negative symptomatic patients. Over time, US has increased in its sensitivity and specificity so it can be used as the initial test in patients presenting with clinical symptoms of CTS because it is now equivalent to EDT. The use of US as a screening test may reduce the number of EDT examinations in patients with suspected CTS, providing additional valuable anatomical information.


  • 1 Gelberman R H, Eaton R, Urbaniak J R. Peripheral nerve compression.  J Bone Joint Surg Am. 1993;  75 1854-1878
  • 2 Watanabe T, Ito H, Morita A et al.. Sonographic evaluation of the median nerve in diabetic patients: comparison with nerve conduction studies.  J Ultrasound Med. 2009;  28(6) 727-734
  • 3 Tagliafico A, Resmini E, Nizzo R et al.. Ultrasound measurement of median and ulnar nerve cross-sectional area in acromegaly.  J Clin Endocrinol Metab. 2008;  93(3) 905-909
  • 4 Padua L, Pazzaglia C, Caliandro P et al.. Carpal tunnel syndrome: ultrasound, neurophysiology, clinical and patient-oriented assessment.  Clin Neurophysiol. 2008;  119(9) 2064-2069
  • 5 Hammer H B, Hovden I A, Haavardsholm E A, Kvien T K. Ultrasonography shows increased cross-sectional area of the median nerve in patients with arthritis and carpal tunnel syndrome.  Rheumatology (Oxford). 2006;  45(5) 584-588
  • 6 Bayrak I K, Bayrak A O, Kale M, Turker H, Diren B. Bifid median nerve in patients with carpal tunnel syndrome.  J Ultrasound Med. 2008;  27(8) 1129-1136
  • 7 Rodríguez-Niedenführ M, Sañudo J R, Vázquez T, Nearn L, Logan B, Parkin I. Median artery revisited.  J Anat. 1999;  195(Pt 1) 57-63
  • 8 Gassner E M, Schocke M, Peer S, Schwabegger A, Jaschke W, Bodner G. Persistent median artery in the carpal tunnel: color Doppler ultrasonographic findings.  J Ultrasound Med. 2002;  21(4) 455-461
  • 9 Dutly-Guinand M, Müller M, Bleuler P, Steiger R. Carpal tunnel syndrome from a thrombosed median artery—four case reports and review of the literature.  , [in German] Handchir Mikrochir Plast Chir. 2009;  41(3) 179-182
  • 10 Fumière E, Dugardeyn C, Roquet M E, Delcour C. US demonstration of a thrombosed persistent median artery in carpal tunnel syndrome.  JBR-BTR. 2002;  85(1) 1-3
  • 11 Pirola E, Hébert-Blouin M N, Amador N, Amrami K K, Spinner R J. Palmaris profundus: one name, several subtypes, and a shared potential for nerve compression.  Clin Anat. 2009;  22(6) 643-648
  • 12 Tsujii M, Hirata H, Morita A, Uchida A. Palmar bowing of the flexor retinaculum on wrist MRI correlates with subjective reports of pain in carpal tunnel syndrome.  J Magn Reson Imaging. 2009;  29(5) 1102-1105
  • 13 Kabakci N T, Kovanlikaya A, Kovanlikaya I. Tractography of the median nerve.  Semin Musculoskelet Radiol. 2009;  13(1) 18-23
  • 14 Stein D, Neufeld A, Pasternak O et al.. Diffusion tensor imaging of the median nerve in healthy and carpal tunnel syndrome subjects.  J Magn Reson Imaging. 2009;  29(3) 657-662
  • 15 Yao L, Gai N. Median nerve cross-sectional area and MRI diffusion characteristics: normative values at the carpal tunnel.  Skeletal Radiol. 2009;  38(4) 355-361
  • 16 Khalil C, Hancart C, Le Thuc V, Chantelot C, Chechin D, Cotten A. Diffusion tensor imaging and tractography of the median nerve in carpal tunnel syndrome: preliminary results.  Eur Radiol. 2008;  18(10) 2283-2291
  • 17 Tehranzadeh J, Ashikyan O, Anavim A, Tramma S. Enhanced MR imaging of tenosynovitis of hand and wrist in inflammatory arthritis.  Skeletal Radiol. 2006;  35(11) 814-822
  • 18 Tehranzadeh J, Ashikyan O, Dascalos J. Magnetic resonance imaging in early detection of rheumatoid arthritis.  Semin Musculoskelet Radiol. 2003;  7(2) 79-94
  • 19 Wu H T, Schweitzer M E, Culp R W. Potential MR signs of recurrent carpal tunnel syndrome: initial experience.  J Comput Assist Tomogr. 2004;  28(6) 860-864
  • 20 Jarvik J G, Yuen E, Haynor D R et al.. MR nerve imaging in a prospective cohort of patients with suspected carpal tunnel syndrome.  Neurology. 2002;  58(11) 1597-1602
  • 21 Chen C K, Chung C B, Yeh L et al.. Carpal tunnel syndrome caused by tophaceous gout: CT and MR imaging features in 20 patients.  AJR Am J Roentgenol. 2000;  175(3) 655-659
  • 22 Campagna R, Pessis E, Feydy A et al.. MRI assessment of recurrent carpal tunnel syndrome after open surgical release of the median nerve.  AJR Am J Roentgenol. 2009;  193(3) 644-650
  • 23 Lee D, van Holsbeeck M T, Janevski P K, Ganos D L, Ditmars D M, Darian V B. Diagnosis of carpal tunnel syndrome. Ultrasound versus electromyography.  Radiol Clin North Am. 1999;  37(4) 859-872, x
  • 24 Martinoli C, Bianchi S, Gandolfo N, Valle M, Simonetti S, Derchi L E. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs.  Radiographics. 2000;  20(Spec No) S199-S213; discussion S213–S217
  • 25 Martinoli C, Bianchi S, Derchi L E. Ultrasonography of peripheral nerves.  Semin Ultrasound CT MR. 2000;  21(3) 205-213
  • 26 Wong S M, Griffith J F, Hui A C, Lo S K, Fu M, Wong K S. Carpal tunnel syndrome: diagnostic usefulness of sonography.  Radiology. 2004;  232(1) 93-99
  • 27 Ziswiler H R, Reichenbach S, Vögelin E, Bachmann L M, Villiger P M, Jüni P. Diagnostic value of sonography in patients with suspected carpal tunnel syndrome: a prospective study.  Arthritis Rheum. 2005;  52(1) 304-311
  • 28 Buchberger W, Judmaier W, Birbamer G, Lener M, Schmidauer C. Carpal tunnel syndrome: diagnosis with high-resolution sonography.  AJR Am J Roentgenol. 1992;  159(4) 793-798
  • 29 Grundberg A B. Carpal tunnel decompression in spite of normal electromyography.  J Hand Surg Am. 1983;  8(3) 348-349
  • 30 Martins R S, Siqueira M G, Simplício H, Agapito D, Medeiros M. Magnetic resonance imaging of idiopathic carpal tunnel syndrome: correlation with clinical findings and electrophysiological investigation.  Clin Neurol Neurosurg. 2008;  110(1) 38-45
  • 31 Mallouhi A, Pültzl P, Trieb T, Piza H, Bodner G. Predictors of carpal tunnel syndrome: accuracy of gray-scale and color Doppler sonography.  AJR Am J Roentgenol. 2006;  186(5) 1240-1245
  • 32 Klauser A, Stadlbauer K H, Frauscher F et al.. Value of transducer positions in the measurement of finger flexor tendon thickness by sonography.  J Ultrasound Med. 2004;  23(3) 331-337
  • 33 De Zordo T, Mur E, Bellmann-Weiler R et al.. US guided injections in arthritis.  Eur J Radiol. 2009;  71(2) 197-203
  • 34 Wiesler E R, Chloros G D, Cartwright M S, Smith B P, Rushing J, Walker F O. The use of diagnostic ultrasound in carpal tunnel syndrome.  J Hand Surg Am. 2006;  31(5) 726-732
  • 35 Koyuncuoglu H R, Kutluhan S, Yesildag A, Oyar O, Guler K, Ozden A. The value of ultrasonographic measurement in carpal tunnel syndrome in patients with negative electrodiagnostic tests.  Eur J Radiol. 2005;  56(3) 365-369
  • 36 Yesildag A, Kutluhan S, Sengul N et al.. The role of ultrasonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome.  Clin Radiol. 2004;  59(10) 910-915
  • 37 Hammer H B, Hovden I A, Haavardsholm E A, Kvien T K. Ultrasonography shows increased cross-sectional area of the median nerve in patients with arthritis and carpal tunnel syndrome.  Rheumatology (Oxford). 2006;  45(5) 584-588
  • 38 Sernik R A, Abicalaf C A, Pimentel B F, Braga-Baiak A, Braga L, Cerri G G. Ultrasound features of carpal tunnel syndrome: a prospective case-control study.  Skeletal Radiol. 2008;  37(1) 49-53
  • 39 Duncan I, Sullivan P, Lomas F. Sonography in the diagnosis of carpal tunnel syndrome.  AJR Am J Roentgenol. 1999;  173(3) 681-684
  • 40 Chen P, Maklad N, Redwine M, Zelitt D. Dynamic high-resolution sonography of the carpal tunnel.  AJR Am J Roentgenol. 1997;  168(2) 533-537
  • 41 Alemán L, Berná J D, Reus M, Martínez F, Doménech-Ratto G, Campos M. Reproducibility of sonographic measurements of the median nerve.  J Ultrasound Med. 2008;  27(2) 193-197
  • 42 Yucel A, Yilmaz O, Babaoglu S, Acar M, Degirmenci B. Sonographic findings of the median nerve and prevalence of carpal tunnel syndrome in patients with Parkinson's disease.  Eur J Radiol. 2008;  67(3) 546-550
  • 43 Klauser A S, Halpern E J, De Zordo T et al.. Carpal tunnel syndrome assessment with US: value of additional cross-sectional area measurements of the median nerve in patients versus healthy volunteers.  Radiology. 2009;  250(1) 171-177
  • 44 Hobson-Webb L D, Massey J M, Juel V C, Sanders D B. The ultrasonographic wrist-to-forearm median nerve area ratio in carpal tunnel syndrome.  Clin Neurophysiol. 2008;  119(6) 1353-1357
  • 45 Bianchi S, Martinoli C. Wrist. In: Baert AL, Knauth M, Sartor K Ultrasound of the Musculoskeletal System. Berlin, Germany; Springer 2007: 425-494
  • 46 Ahn S Y, Hong Y H, Koh Y H, Chung Y S, Lee S H, Yang H J. Pressure measurement in carpal tunnel syndrome: correlation with electrodiagnostic and ultrasonographic findings.  J Korean Neurosurg Soc. 2009;  46(3) 199-204
  • 47 Tagliafico A, Pugliese F, Bianchi S et al.. High-resolution sonography of the palmar cutaneous branch of the median nerve.  AJR Am J Roentgenol. 2008;  191(1) 107-114
  • 48 Seror P. Sonography and electrodiagnosis in carpal tunnel syndrome diagnosis, an analysis of the literature.  Eur J Radiol. 2008;  67(1) 146-152
  • 49 Wilson D. Ultrasound assessment of carpal tunnel syndrome.  Clin Radiol. 2004;  59(10) 909
  • 50 Kamolz L P, Schrögendorfer K F, Rab M, Girsch W, Gruber H, Frey M. The precision of ultrasound imaging and its relevance for carpal tunnel syndrome.  Surg Radiol Anat. 2001;  23(2) 117-121
  • 51 Karadağ Y S, Karadağ O, Ciçekli E et al.. Severity of carpal tunnel syndrome assessed with high frequency ultrasonography.  Rheumatol Int. 2010;  30(6) 761-765
  • 52 Moran L, Perez M, Esteban A, Bellon J, Arranz B, del Cerro M. Sonographic measurement of cross-sectional area of the median nerve in the diagnosis of carpal tunnel syndrome: correlation with nerve conduction studies.  J Clin Ultrasound. 2009;  37(3) 125-131
  • 53 Lundborg G, Gelberman R H, Minteer-Convery M, Lee Y F, Hargens A R. Median nerve compression in the carpal tunnel—functional response to experimentally induced controlled pressure.  J Hand Surg Am. 1982;  7(3) 252-259
  • 54 Kluge S, Kreutziger J, Hennecke B, Vögelin E. Inter- and intraobserver reliability of predefined diagnostic levels in high-resolution sonography of the carpal tunnel syndrome— a validation study on healthy volunteers.  Ultraschall Med. 2010;  31(1) 43-47
  • 55 Chern T C, Jou I M, Chen W C, Wu K C, Shao C J, Shen P C. An ultrasonographic and anatomical study of carpal tunnel, with special emphasis on the safe zones in percutaneous release.  J Hand Surg Eur Vol. 2009;  34(1) 66-71
  • 56 Abicalaf C A, de Barros N, Sernik R A et al.. Ultrasound evaluation of patients with carpal tunnel syndrome before and after endoscopic release of the transverse carpal ligament.  Clin Radiol. 2007;  62(9) 891-894; discussion 895–896
  • 57 Pang H N, Puhaindran M, Yong F C. Fibrolipoma of multiple nerves in the wrist.  Singapore Med J. 2009;  50(8) e283-e286
  • 58 Pastare D, Therimadasamy A K, Lee E, Wilder-Smith E P. Sonography versus nerve conduction studies in patients referred with a clinical diagnosis of carpal tunnel syndrome.  J Clin Ultrasound. 2009;  37(7) 389-393

Andrea S KlauserM.D. 

Department of Diagnostic Radiology, Anichstrasse 35

Medical University Innsbruck, 6020 Innsbruck, Austria