title: Quantification of blood flow in the carotid arteries: comparison of Doppler ultrasound and three different phase-contrast magnetic resonance imaging sequences.
abstract: OBJECTIVE
  To compare blood flow velocities in the carotid arteries measured with three different magnetic resonance (MR) phase-contrast imaging techniques and with percutaneous Doppler ultrasound.
  
  
  METHODS
  Fourteen healthy male volunteers with a mean age of 33 +/- 3.8 years were studied. Ultrasound and MR phase velocity mapping of both common carotid arteries (n = 28) was performed within 5 hours. A two-dimensional fast low-angle shot sequence with retrospective cardiac gating, a sequence with prospective cardiac triggering, and a breath-hold sequence with prospective cardiac triggering were used. Resistance indexes and pulsatility indexes were calculated for all modalities.
  
  
  RESULTS
  The comparison of flow velocities obtained with ultrasound and the different MR techniques led to a moderate correlation of the retrospective gated and prospective triggered MR techniques (eg, r = 0.73 for maximum systolic velocity). The worst correlation was found between the breath-hold technique and retrospective cardiac gating (eg, r = 0.004 for pulsatility index). There was a weak correlation of all three MR sequences compared with ultrasound (r = 0.19-0.60)
  
  
  CONCLUSIONS
  A moderate correlation was found between velocities and indexes measured with the prospective cardiac-triggered phase-contrast MR technique and the retrospective cardiac-gated phase-contrast MR technique. A weak correlation was found between the three different MR techniques and ultrasound, as well as between the breath-hold prospective cardiac-triggered MR sequence and both of the other MR sequences. The influence of temporal and spatial resolution on MR phase-contrast velocity mapping was confirmed.
authors.affiliation: Department of Diagnostic Radiology, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, D-93042 Regensburg, Germany. Johannes.Seitz@Klinik.Uni-Regensburg.de
authors.forename: J
authors.initials: J
authors.lastname: Seitz
authors.forename: M
authors.initials: M
authors.lastname: Strotzer
authors.forename: T
authors.initials: T
authors.lastname: Wild
authors.forename: W R
authors.initials: WR
authors.lastname: Nitz
authors.forename: M
authors.initials: M
authors.lastname: Völk
authors.forename: M
authors.initials: M
authors.lastname: Lenhart
authors.forename: S
authors.initials: S
authors.lastname: Feuerbach
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012016:Reference Values; D018608:Ultrasonography, Doppler