title: Comparing velocity and fluid shear stress in a stenotic phantom with steady flow: phase-contrast MRI, particle image velocimetry and computational fluid dynamics.
abstract: OBJECTIVE
  This study aims to validate phase-contrast magnetic resonance imaging (PC-MRI) measurements of a steady flow through a severe stenotic phantom using particle image velocimetry (PIV) and computational fluid dynamics (CFD).
  
  
  METHODS
  The study was performed in an axisymmetric 87 % area stenosis model using an inlet Reynolds number (Re) of 160, corresponding to a jet Re of 444. Velocity patterns and estimated fluid shear stresses from three modalities were analyzed and compared qualitatively and quantitatively.
  
  
  RESULTS
  Visual analysis via contour subtraction and Bland-Altman plots showed good agreement for flow velocities and less agreement for maximum shear stress (MSS). The Pearson's coefficients of correlation between PC-MRI and PIV were 0.97 for the velocity field and 0.82 for the MSS. The corresponding parameters between PC-MRI and CFD were 0.96 and 0.84, respectively.
  
  
  CONCLUSIONS
  Findings indicate that PC-MRI can be implemented to estimate velocity flow fields and MSS; however, this method is not sufficiently accurate to quantify the MSS at regions of high shear rate.
authors.affiliation: Department of Electrical and Computer Engineering, University of Louisville, 2210 S Brook St, Shumaker Research Building, Room 216, Louisville, KY, 40292, USA, imankhodarahmi@yahoo.com.
authors.forename: Iman
authors.initials: I
authors.lastname: Khodarahmi
mesh_terms: D003251:Constriction, Pathologic; D057446:Hydrodynamics; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*