title: Cross sectional area reference values for sonography of peripheral nerves and brachial plexus.
abstract: OBJECTIVE
  Ultrasound measurements of the cross sectional area (CSA) variability have been recently introduced to quantify pathological changes in peripheral nerves (PN).
  
  
  METHODS
  Reference values from 75 healthy subjects and their correlation to age, height, weight and sex are reported.
  
  
  RESULTS
  The mean values in PN were: (1) intranerve CSA-variability: median 1.05 (SD ± 0.13), ulnar 1.53 (SD ± 0.51), fibular 1.33 (SD ± 0.37), tibial 1.39 (SD ± 0.39), (2) internerve CSA-variability 1.76 (SD ± 0.37), (3) intraplexus CSA-variability 1.52 (SD ± 0.37), (4) side-to-side difference ratio of the CSA-variability: median 1.21 (SD ± 0.04), ulnar 1.2 (SD ± 0.25), fibular 1.19 (SD ± 0.23), tibial 1.28 (SD ± 0.24) and brachial plexus 1.19 (SD ± 0.23). CSA did not correlate with height in PN, but correlated with weight in the ulnar nerve [Guyon's canal, r = 0.411, p = 0.0237, elbow r = 0.409, p = 0.0248]. Significant changes between sex were found only in the ulnar (Guyon's canal, p = 0.0265), fibular (popliteal fossa, p = 0.0336) and sural nerve (p = 0.048). CSA decreased with age in the median (axilla, p = 0.0236), and radial nerve (spiral groove, p = 0.0037) and increased in the tibial nerve (ankle, p < 0.0001).
  
  
  CONCLUSIONS
  The CSA reference values reported seem to correlate at certain sites with age, weight and sex but not with height.
  
  
  CONCLUSIONS
  The new CSA variability measures may be helpful in investigating pathologies of the PN.
authors.affiliation: Department of Neurology, St. Josef-Hospital, Ruhr University, Bochum, Germany. antonis.kerasnoudis@gmail.com
authors.forename: Antonios
authors.initials: A
authors.lastname: Kerasnoudis
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Pitarokoili
authors.forename: Volker
authors.initials: V
authors.lastname: Behrendt
authors.forename: Ralf
authors.initials: R
authors.lastname: Gold
authors.forename: Min-Suk
authors.initials: MS
authors.lastname: Yoon
mesh_terms: D001835:Body Weight; D001917:Brachial Plexus / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D010525:Peripheral Nerves / Q000000981:diagnostic imaging*; D011826:Radial Nerve / Q000000981:diagnostic imaging; D012016:Reference Values; D013497:Sural Nerve / Q000000981:diagnostic imaging; D013979:Tibial Nerve / Q000000981:diagnostic imaging; D014459:Ulnar Nerve / Q000000981:diagnostic imaging; D014463:Ultrasonography; D014953:Wrist / Q000000981:diagnostic imaging
keywords: Internerve cross sectional area variability; Intranerve; Intraplexus cross sectional area variability; Nerve ultrasound; Reference values