title: Reproducibility of sonographic measurements of the median nerve.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the reproducibility of median nerve cross-sectional area (CSA) measurements using the indirect method (ellipsoid formula) and the direct or tracing method.
  
  
  METHODS
  The median nerve CSA was measured in 22 wrists of patients with carpal tunnel syndrome by means of high-frequency sonography. Measurements were made at the level of the pisiform bone by a standardized sonographic examination protocol. Two observers with different levels of experience performed the measurements, independently and blinded. An analysis of reliability was carried out, and the concordance between the methods was determined with parametric statistical tests.
  
  
  RESULTS
  The results point to good reproducibility of the median nerve CSA measurements obtained by both methods, whether performed by an experienced observer or by an inexperienced observer after a short learning period.
  
  
  CONCLUSIONS
  The results suggest sonography for median nerve CSA measurements is reproducible by either the direct or indirect method when a standardized sonographic examination protocol is used.
authors.affiliation: Department of Radiology, Virgen de la Arrixaca University Hospital, El Palmar, Murcia, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Alemán
authors.forename: Juan D
authors.initials: JD
authors.lastname: Berná
authors.forename: Manuel
authors.initials: M
authors.lastname: Reus
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez
authors.forename: Ginés
authors.initials: G
authors.lastname: Doménech-Ratto
authors.forename: Matilde
authors.initials: M
authors.lastname: Campos
mesh_terms: D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D015203:Reproducibility of Results; D014463:Ultrasonography