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VOLUME 26 , ISSUE 4 ( December, 2015 ) > List of Articles


Ultrasound: A Screening Tool for Carpal Tunnel Syndrome

Bobeena Rachel Chandy, M. Betty, Henry Prakash Magimairaj, Binu P. Thomas, George Tharion

Citation Information : Chandy BR, Betty M, Magimairaj HP, Thomas BP, Tharion G. Ultrasound: A Screening Tool for Carpal Tunnel Syndrome. Indian J Phy Med Rehab 2015; 26 (4):102-108.

DOI: 10.5005/ijopmr-26-4-102

Published Online: 01-12-2015

Copyright Statement:  Copyright © 2015; The Author(s).



Electrodiagnostic test is considered as the gold standard for diagnosis of carpal tunnel syndrome (CTS). Ultrasonography provides a simple non-invasive means of visualising peripheral nerve pathology.


The objective of the study was to assess the role of ultrasonography in CTS and its correlation with the present day gold standard of nerve conduction studies (NCS).

Materials and Methods

A prospective cohort size of 100 subjects was calculated based on a hypothesized sensitivity of 90% and a confidence interval of 85-95%. All 100 subjects, 64 controls and 36 patients underwent nerve conduction studies and USG. Transverse images of the median nerve were obtained at three levels: proximal to the carpal tunnel inlet, at the carpal tunnel inlet and at the carpal tunnel outlet. The flattening ratio was also assessed at the tunnel inlet and outlet. Statistical analysis was done to corelate the ultrasound findings at each level with nerve conduction studies and calculation of the positive and negative predictive values. The cut offs of the cross-sectional areas of the median nerve at the three anatomical levels on ultrasonography were taken at the best sensitivity and specificity according to the ROC curve.


We found that at any one anatomical level, the sensitivity of ultrasound to detect carpal tunnel syndrome by increase in the cross-sectional area of median nerve as compared to the nerve conduction studies is 90%.


At 45% specificity, ultrasonography could be used as a non-invasive and easily available screening tool in carpal tunnel syndrome. Also, the best level to look for nerve compression is at the level of the carpal tunnel inlet.

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  1. Carpal tunnel syndrome. Curr Opin Neurol 2005;18:581-5.
  2. Prevalence of carpal tunnel syndrome in a general population. JAMA 1999;282:153-8.
  3. What is the diagnostic value of ultrasonography compared to physical evaluation in patients with idiopathic carpal tunnel syndrome? Clin Exp Rheumatol 2007;25:853-9.
  4. The use of diagnostic ultrasound in carpal tunnel syndrome. J Hand Surg Am 2006;31:726-32.
  5. The role of ultrasonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome. Clin Radiol 2004;59:910-5.
  6. Carpal tunnel syndrome: diagnostic usefulness of sonography. Radiology. 2004;232:93-9.
  7. Ultrasound assessment of carpal tunnel syndrome. Clin Radiol 2004;59:909.
  8. High-resolution sonography versus EMG in the diagnosis of carpal tunnel syndrome. J Neurol Neurosurg Psychiatry 2008;79:63-7.
  9. Ultrasound features of carpal tunnel syndrome: a prospective case-control study. Skeletal Radiol 2008;37:49-53.
  10. Carpal tunnel syndrome: usefulness of sonography. Eur Radiol 2000;10:1920-5.
  11. Ultrasonographic measurement of median nerve cross-sectional area in idiopathic carpal tunnel syndrome: diagnostic accuracy. Muscle Nerve 2002;26:798-803.
  12. Diagnostic utility of ultrasonography versus nerve conduction studies in mild carpal tunnel syndrome. Arthritis Rheum 2008;59:357-66.
  13. Diagnosis of carpal tunnel syndrome. Ultrasound versus electromyography. Radiol Clin North Am 1999;37:859-72.
  14. Correlation of high-resolution ultrasonographic findings with the clinical symptoms and electrodiagnostic data in carpal tunnel syndrome. Ann Plast Surg 2005;54:20-3.
  15. Ultrasound imaging in the diagnosis of carpal tunnel syndrome and its relevance to clinical evaluation. Joint Bone Spine 2005;72:142-5.
  16. High resolution sonography of the carpal tunnel. J Ultrasound Med 1991;10:531-7.
  17. Ultrasonography in carpal tunnel syndrome: comparison with electrophysiological stage and motor unit number estimate. Muscle Nerve 2007;35:344-8.
  18. What is the diagnostic value of ultrasonography compared to physical evaluation in patients with idiopathic carpal tunnel syndrome. Clin Exp Rheumatol 2007:854-9.
  19. Practice parameter for carpal tunnel syndrome. Neurology 1993:2406-9.
  20. Carpal Tunnel Syndrome in Indian Patients: Use of Modified Questionnaries for Assessment. J Hand Surg Eur 2009;34:671-8.
  21. J, Thomas B, Edgell SE. Determining the Sensitivity and Specificity of common diagnostic tests for Carpal Tunnel Syndrome using latent class analysis. Plast Reconstr Surg 2005;116:502-7.
  22. Practice parameters for electrodiagnostic studies in carpal tunel syndrome: Summary statement. Muscle Nerve 2002;25:918-22.
  23. Clinical neurophysiology. 1999.
  24. Sensitivity, Specificity and Variability of Nerve Conduction Velocity Measurements in Carpal Tunnel Syndrome. Arch Phys Med Rehabil 2005;86:12-6.
  25. Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. AAEM Quality Assurance Committee. Muscle Nerve 1993;16:1392-414.
  26. Anatomical variations of the median nerve in the carpal tunnel. J Hand Surg 1977;2:44.
  27. Carpal tunnel sonography by the rheumatologist versus nerve conduction study by the neurologist. J Rheumatol 2001;28:62-9.
  28. Sonography in the diagnosis of carpal tunnel syndrome. AJR Am J Roentgenol 1999;173:681-4.
  29. The value of ultrasonographic measurement in carpal tunnel syndrome in patients with negative electrodiagnostic tests. Eur J Radiol 2005;56:365-9.
  30. Carpal tunnel syndrome -is high-frequency ultrasound a useful diagnostic tool? J Hand Surg Br 2003;28:77-9.
  31. Diagnostic precision of ultrasonography in patients with carpal tunnel syndrome. Am J Phys Med Rehabil 2005;84:443-50.
  32. The precision of ultrasound imaging and its relevance for carpal tunnel syndrome. Surg Radiol Anat 2001;23:117-21.
  33. Sonography in the diagnosis of carpal tunnel syndrome: a critical review of the literature. Muscle Nerve 2003; 27: 26-33.
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