title: Measuring pulsatile flow in cerebral arteries using 4D phase-contrast MR imaging.
abstract: OBJECTIVE
  4D PCMRI can be used to quantify pulsatile hemodynamics in multiple cerebral arteries. The aim of this study was to compare 4D PCMRI and 2D PCMRI for assessments of pulsatile hemodynamics in major cerebral arteries.
  
  
  METHODS
  We scanned the internal carotid artery, the anterior cerebral artery, the basilar artery, and the middle cerebral artery in 10 subjects with a single 4D and multiple 2D PCMRI acquisitions by use of a 3T system and a 32-channel head coil. We assessed the agreement regarding net flow and the volume of arterial pulsatility (ΔV) for all vessels.
  
  
  RESULTS
  2D and 4D PCMRI produced highly correlated results, with r = 0.86 and r = 0.95 for ΔV and net flow, respectively (n = 69 vessels). These values increased to r = 0.93 and r = 0.97, respectively, during investigation of a subset of measurements with <5% variation in heart rate between the 4D and 2D acquisition (n = 31 vessels). Significant differences were found for ICA and MCA net flow (P = .004 and P < .001, respectively) and MCA ΔV (P = .006). However, these differences were attenuated and no longer significant when the subset with stable heart rate (n = 31 vessels) was analyzed.
  
  
  CONCLUSIONS
  4D PCMRI provides a powerful methodology to measure pulsatility of the larger cerebral arteries from a single acquisition. A large part of differences between measurements was attributed to physiologic variations. The results were consistent with 2D PCMRI.
authors.affiliation: Department of Radiation Sciences.
authors.forename: A
authors.initials: A
authors.lastname: Wåhlin
authors.forename: K
authors.initials: K
authors.lastname: Ambarki
authors.forename: R
authors.initials: R
authors.lastname: Birgander
authors.forename: O
authors.initials: O
authors.lastname: Wieben
authors.forename: K M
authors.initials: KM
authors.lastname: Johnson
authors.forename: J
authors.initials: J
authors.lastname: Malm
authors.forename: A
authors.initials: A
authors.lastname: Eklund
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods; D002536:Cerebral Arteries / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009474:Neurons; D009929:Organ Size; D011673:Pulsatile Flow / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult