title: Validity and reliability of nerve and muscle ultrasound.
abstract: BACKGROUND
  Nerve and muscle ultrasound has been studied in several conditions, but validity and reliability have not been assessed systematically.
  
  
  METHODS
  Nerve cross-sectional area and muscle thickness were measured ultrasonographically at several sites in 4 cadavers, which were then dissected, and actual measurements were obtained. To assess intrarater and interrater reliability, between 3 and 5 ultrasonographers, with varying experience levels, made repeated measurements on healthy volunteers.
  
  
  RESULTS
  Correlation coefficients for nerve and muscle validity were >0.968 (P < 0.001), and for intrarater reliability were >0.901 (P < 0.001) for still and real-time images. Correlation coefficients for interrater reliability were more varied, but for still images they were all significant at the P < 0.001 (0.542-0.998) level, and for real-time images they were significant at the P < 0.05 level for half the sites (0.243-0.981).
  
  
  CONCLUSIONS
  Overall, nerve and muscle ultrasound is a valid and reliable diagnostic imaging technique.
authors: Department of Neurology, Wake Forest University School of Medicine, Main Floor Reynolds Tower, Winston-Salem, North Carolina 27157, USA. mcartwri@wakehealth.edu
authors: Michael S
authors: MS
authors: Cartwright
authors: Samantha
authors: S
authors: Demar
authors: Leah P
authors: LP
authors: Griffin
authors: Nikhil
authors: N
authors: Balakrishnan
authors: Jessica M
authors: JM
authors: Harris
authors: Francis O
authors: FO
authors: Walker
mesh_terms: D002102:Cadaver; D006801:Humans; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D015588:Observer Variation; D009929:Organ Size; D010525:Peripheral Nerves / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014463:Ultrasonography