title: The use of diagnostic ultrasound in carpal tunnel syndrome.
abstract: OBJECTIVE
  Traditional evaluation of suspected carpal tunnel syndrome (CTS) involves a thorough history, physical examination, and nerve conduction velocity studies (NCS). Ultrasound is used widely in Europe and has gained acceptance in the United States in the diagnosis of various musculoskeletal disorders. The purpose of this study was to document the ultrasonographic measurement difference in median nerve size between patients with CTS and controls and to correlate these findings with NCS findings, thereby allowing us to test the validity of ultrasound as a diagnostic modality for CTS.
  
  
  METHODS
  Forty-four wrists in 26 CTS patients and 86 wrists in 43 asymptomatic volunteers were imaged using a real-time ultrasound scanner with a 12/5 MHz linear-array transducer. The cross-sectional area of the median nerve was measured at the level of the distal wrist crease in both CTS patients and controls. All CTS patients had NCS. The ultrasonographic median nerve area was compared for the 2 groups and correlation analysis between ultrasonographic nerve sizes and NCS findings was performed.
  
  
  RESULTS
  The average cross-sectional area of the median nerve at the distal wrist crease was 9 mm(2) in asymptomatic volunteers and 14 mm(2) in CTS patients. For the CTS patients the Pearson correlation coefficient between ultrasound nerve measurement and NCS values was 0.37, suggesting that higher values of ultrasound measurements are associated with abnormal NCS findings.
  
  
  CONCLUSIONS
  Our results indicate that high-resolution ultrasound is informative in the evaluation of CTS and shows enlargement of the median nerve at the distal wrist crease in symptomatic patients. Therefore it is a reliable modality for imaging the wrist in patients with CTS. In addition ultrasound is well tolerated and safe.
  
  
  METHODS
  Diagnostic, Level I.
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. ewiesler@wfubmc.edu
authors.forename: Ethan R
authors.initials: ER
authors.lastname: Wiesler
authors.forename: George D
authors.initials: GD
authors.lastname: Chloros
authors.forename: Michael S
authors.initials: MS
authors.lastname: Cartwright
authors.forename: Beth P
authors.initials: BP
authors.lastname: Smith
authors.forename: Julia
authors.initials: J
authors.lastname: Rushing
authors.forename: Francis O
authors.initials: FO
authors.lastname: Walker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019412:Anatomy, Cross-Sectional; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging*; D003943:Diagnostic Techniques, Neurological; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009431:Neural Conduction; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography