title: Magnetic resonance imaging versus Doppler guide wire in the assessment of coronary flow reserve in patients with coronary artery disease.
abstract: BACKGROUND
  Coronary flow velocity reserve (CFVR), defined as the ratio of maximal hyperaemic to baseline flow velocity, has been validated as a marker of physiological significance of a coronary lesion. Clinically, this parameter is measured invasively during X-ray angiography using the Doppler guide wire. With magnetic resonance (MR) imaging it is possible to quantify CFVR non-invasively.
  
  
  METHODS
  The purpose of the study was to compare CFVR, acquired with MR imaging and the Doppler guide wire in patients with coronary artery disease.
  
  
  METHODS
  Twenty-two patients suffering from one- or two-vessel coronary artery disease as derived from diagnostic X-ray coronary angiography were included. Coronary flow velocity reserve was measured at baseline and during maximal hyperaemia, obtained by intravenous administration of adenosine using MR phase contrast velocity quantification. Within 2 weeks CFVR was measured invasively with a Doppler guide wire.
  
  
  RESULTS
  In 26 coronary arteries CFVR was acquired with both techniques. Mean CFVR in the stenosed and healthy reference arteries was 1.5 +/- 0.7 and 2.7 +/- 1.0 (P < 0.01) respectively for MR measurements and 1.9 +/- 0.7 and 3.1 +/- 0.6 (P < 0.01) respectively for Doppler measurements. Bland-Altman analysis revealed a non-significant mean difference between the two techniques of 0.4 +/- 1.2.
  
  
  CONCLUSIONS
  In a selected group of stable patients with coronary artery disease MR flow velocity quantification provides non-invasive data equivalent to the invasive Doppler guide wire data. Variability in both the MR and Doppler ultrasound measurement resulted in a significant scatter of data without systematic difference.
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands. wlf.bedaux@VUmc.nl
authors.forename: Willemijn L F
authors.initials: WL
authors.lastname: Bedaux
authors.forename: Mark B M
authors.initials: MB
authors.lastname: Hofman
authors.forename: Carel C
authors.initials: CC
authors.lastname: de Cock
authors.forename: Martin G
authors.initials: MG
authors.lastname: Stoel
authors.forename: Cees A
authors.initials: CA
authors.lastname: Visser
authors.forename: Albert C
authors.initials: AC
authors.lastname: van Rossum
mesh_terms: D001783:Blood Flow Velocity; D016000:Cluster Analysis; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D012984:Software; D018608:Ultrasonography, Doppler; D018084:Ultrasonography, Interventional