title: Velocity Measurement in Carotid Artery: Quantitative Comparison of Time-Resolved 3D Phase-Contrast MRI and Image-based Computational Fluid Dynamics.
abstract: BACKGROUND
  Understanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies.
  
  
  OBJECTIVE
  Three-dimensional velocity vector field in carotid bifurcation is visualized using TR 3D phase-contrast magnetic resonance imaging (TR 3D PC MRI) and computational fluid dynamics (CFD). This study aimed to present a qualitative and quantitative comparison of the velocity vector field obtained by each technique.
  
  
  METHODS
  MR imaging was performed on a 30-year old male normal subject. TR 3D PC MRI was performed on a 3 T scanner to measure velocity in carotid bifurcation. 3D anatomical model for CFD was created using images obtained from time-of-flight MR angiography. Velocity vector field in carotid bifurcation was predicted using CFD and PC MRI techniques. A statistical analysis was performed to assess the agreement between the two methods.
  
  
  RESULTS
  Although the main flow patterns were the same for the both techniques, CFD showed a greater resolution in mapping the secondary and circulating flows. Overall root mean square (RMS) errors for all the corresponding data points in PC MRI and CFD were 14.27% in peak systole and 12.91% in end diastole relative to maximum velocity measured at each cardiac phase. Bland-Altman plots showed a very good agreement between the two techniques. However, this study was not aimed to validate any of methods, instead, the consistency was assessed to accentuate the similarities and differences between Time-resolved PC MRI and CFD.
  
  
  CONCLUSIONS
  Both techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (RCA). PC MRI represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. However, limitations of each technique should be considered while interpreting results.
authors.affiliation: Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Sarrami-Foroushani
authors.affiliation: Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Nasr Esfahany
authors.affiliation: Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Nasiraei Moghaddam
authors.affiliation: Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Saligheh Rad
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kavous
authors.initials: K
authors.lastname: Firouznia
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Madjid
authors.initials: M
authors.lastname: Shakiba
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Ghanaati
authors.affiliation: Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom.
authors.forename: Iain David
authors.initials: ID
authors.lastname: Wilkinson
authors.affiliation: Department of Mechanical Engineering, The University of Sheffield, Sheffield, United Kingdom.
authors.forename: Alejandro Federico
authors.initials: AF
authors.lastname: Frangi
keywords: Carotid Bifurcation; Fluid Dynamics; Time-Resolved Three-Dimensional Phase-Contrast Magnetic Resonance Imaging (TR 3D PC MRI)