title: Subtracted vortex centers path line method with cinematic angiography for measurement of flow speed in cerebral aneurysms.
abstract: OBJECTIVE
  The assessment of blood flow speed by imaging modalities is of increasing importance for endovascular treatment, such as stent implantation, of cerebral aneurysms. The subtracted vortex centers path line method (SVC method) utilizes image post-processing for determining flow quantitatively. In current practice, intra-aneurysmal flow in an in vitro model is visualized by laser sheet translumination and digitally recorded. In this study, we applied this method to cinematic angiography (CA), which is the preferred imaging method for endovascular interventions, to analyse hemodynamic changes. The SVC method was applied to the images and compared with results of the slipstream line method with colored fluid.
  
  
  METHODS
  A transparent tubular model was constructed of silicone which included an aneurysm 10 mm in diameter and having a 5 mm neck on a straight parent artery with a diameter of 3.5 mm. The model was integrated into a pulsatile circulation system. By CA, successive images at 25 frames/s with injection of contrast were obtained.
  
  
  CONCLUSIONS
  Rotating vortexes of contrast, which advanced along the wall of the aneurysm, were observed in successive images of the aneurysm cavity. This phenomenon was also observed in the successive images with the slipstream line method. The speed of the vortex center was calculated and the results show that the vortex speed of CA was the same as that under the slipstream line method. This indicates the possibility of applying the SVC method to medical imaging equipment for analysis of the flow in aneurysms containing stent.
authors.affiliation: Biofluid Control laboratory, Institute of Fluid Science, Tohoku University, Sendai 980-8577, Japan. ohta@biofluid.ifs.tohoku.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohta
authors.forename: Naoko
authors.initials: N
authors.lastname: Fujimura
authors.forename: Luca
authors.initials: L
authors.lastname: Augsburger
authors.forename: Krisztina
authors.initials: K
authors.lastname: Barath
authors.forename: Hasan
authors.initials: H
authors.lastname: Yilmaz
authors.forename: German
authors.initials: G
authors.lastname: Abdo
authors.forename: Karl-Olof
authors.initials: KO
authors.lastname: Lovblad
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Rüfenacht
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D002533:Cerebral Angiography / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D002532:Intracranial Aneurysm / Q000503:physiopathology*; D020768:Middle Cerebral Artery / Q000503:physiopathology; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D012039:Regional Blood Flow / Q000502:physiology