title: Reproducibility of ultrasonographic measures in internal jugular veins of normal subjects.
abstract: OBJECTIVE
  To assess the reproducibility of ultrasonographic quantitative parameters of internal jugular veins (IJV) in normal subjects.
  
  
  METHODS
  Thirty IJV of 15 normal volunteers were prospectively evaluated by means of duplex Doppler ultrasonography (US). Patency, presence of thrombosis, characteristics of the vein wall, compressibility, area of vein both in rest and during Valsalva maneuver, expiratory flow speed, Valsalva flow speed, jugular flow in each side, and total jugular flow were registered in all cases. Two measures were performed in each subject.
  
  
  RESULTS
  High reproducibility was encountered in jugular flow (R=0.95) and in area during Valsalva (R=0.90) in the left IJV. Low reproducibility was found in Valsalva flow speed of the left side (R=0.35). The remaining measurements had a good reproducibility (R=0.50-0.75).
  
  
  CONCLUSIONS
  The ultrasonographic parameters of IJV in normal subjects show an adequate grade of reproducibility. Thus, duplex Doppler US can be used as a reliable method for evaluation or comparison of IJV in different situations of future studies.
authors.affiliation: Department of Otorhinolaryngology, La Paz Hospital, Autonomous University of Madrid, C/Arzobispo Morcillo no 12, 1degreeC, 28029, Madrid, Spain. jidediegompprim@retemail.es
authors.forename: J I
authors.initials: JI
authors.lastname: De Diego
authors.forename: M P
authors.initials: MP
authors.lastname: Prim
authors.forename: P
authors.initials: P
authors.lastname: Garcia-Raya
authors.forename: R
authors.initials: R
authors.lastname: Madero
authors.forename: J
authors.initials: J
authors.lastname: Gavilan
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D007601:Jugular Veins / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler