title: [In vitro evaluation of the intravasal Doppler guide wire: determination of hemodynamic effects of stenoses in a flow model].
abstract: OBJECTIVE
  In a pulsatile hydraulic model, haemodynamic changes caused by stenoses were assessed using an intravascular Doppler guide wire.
  
  
  METHODS
  In defined stenoses (25, 50, 75 and 87.5% diameter ratio), and with and without collateral flow, a 0.018 inch (0.46 mm) 12 MHz Doppler guide wire was assessed. Flow velocity measurements were taken 20 mm proximal, in, and 20 mm distal to the stenoses. Average peak velocity (APV) and ratios of pre-/poststenotic velocities and pre-/intrastenotic velocities of APV were compared with the grade of stenosis. The degree of the stenosis calculated by the ratio of the cross-sectional area, using the pre- and intrastenotic APV, was correlated with the actual stenosis.
  
  
  RESULTS
  The intrastenotic APV increased significantly (APV proximal to the stenosis 15.15 +/- 4.5 cm/s, intrastenotic APV 134.8 +/- 130.9, p < 0.01, Wilcoxon-Mann-Whitney test). The difference between APV pre- and poststenotic was not significant (p > 0.5). Concerning the grade of stenosis the ratio APV pre-/intrastenotic and the consecutively calculated cross-sectional area stenoses was the best predictor (correlation with the known cross-sectional area stenosis r = 0.94 Pearson).
  
  
  CONCLUSIONS
  Using the Doppler guide wire, APV measurements pre- and intrastenotic enable a reliable quantification of the grade of stenosis. The stenosis calculated via the cross-sectional area correlates significantly with the actual stenosis.
authors.affiliation: Abteilung für Strahlendiagnostik, Philipps Universität, Marburg.
authors.forename: M
authors.initials: M
authors.lastname: Hoppe
authors.forename: H J
authors.initials: HJ
authors.lastname: Wagner
authors.forename: M
authors.initials: M
authors.lastname: Kunisch
authors.forename: J J
authors.initials: JJ
authors.lastname: Froelich
authors.forename: K J
authors.initials: KJ
authors.lastname: Klose
mesh_terms: D001157:Arterial Occlusive Diseases / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D003251:Constriction, Pathologic / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008961:Models, Structural; D018608:Ultrasonography, Doppler / Q000295:instrumentation