MRI and CFD studies of pulsatile flow in healthy and stenosed carotid bifurcation models.
Pulsatile flow was studied in physiologically realistic models of a normal and a moderately stenosed (30% diameter reduction) human carotid bifurcation. Time-resolved velocity measurements were made using magnetic resonance imaging, from which wall shear stress (WSS) vectors were calculated. Velocity measurements in the inflow and outflow regions were also used as boundary conditions for a computational fluid dynamics (CFD) model. Experimental flow patterns and derived WSS vectors were compared qualitatively with the corresponding CFD predictions. In the stenosed phantom, flow in the bulb region of the "internal carotid artery" was concentrated along the outer wall, with a region of low and recirculating flow near the inner wall. In the normal phantom, the converse was found, with a low flow region near the outer wall of the bulb. Time-averaged WSS and oscillatory shear index were also markedly different for the two phantoms.
Marshall
Ian
I
Department of Medical and Radiological Sciences, Medical Physics, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK. i.marshall@ed.ac.uk
Zhao
Shunzhi
S
Papathanasopoulou
Panorea
P
Hoskins
Peter
P
Xu
Yun
Y
D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000473:pathology / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000503:physiopathology*; D003198:Computer Simulation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D011673:Pulsatile Flow; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength