Minimizing the blood velocity differences between phase-contrast magnetic resonance imaging and computational fluid dynamics simulation in cerebral arteries and aneurysms.
The integration of phase-contrast magnetic resonance images (PC-MRI) and computational fluid dynamics (CFD) is a way to obtain detailed information of patient-specific hemodynamics. This study proposes a novel strategy for imposing a pressure condition on the outlet boundary (called the outlet pressure) in CFD to minimize velocity differences between the PC-MRI measurement and the CFD simulation, and to investigate the effects of outlet pressure on the numerical solution. The investigation involved ten patient-specific aneurysms reconstructed from a digital subtraction angiography image, specifically on aneurysms located at the bifurcation region. To evaluate the effects of imposing the outlet pressure, three different approaches were used, namely: a pressure-fixed (P-fixed) approach; a flow rate control (Q-control) approach; and a velocity-field-optimized (V-optimized) approach. Numerical investigations show that the highest reduction in velocity difference always occurs in the V-optimized approach, where the mean of velocity difference (normalized by inlet velocity) is 19.3%. Additionally, the highest velocity differences appear near to the wall and vessel bifurcation for 60% of the patients, resulting in differences in wall shear stress. These findings provide a new methodology for PC-MRI integrated CFD simulation and are useful for understanding the evaluation of velocity difference between the PC-MRI and CFD.
Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan. a.mohdadib@biomech.me.es.osaka-u.ac.jp.
Mohd Azrul Hisham
http://orcid.org/0000-0003-4359-5043
MAH
Mohd Adib
Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
Satoshi
S
Ii
Department of Radiology, Graduate School of Medicine, Osaka University, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Yoshiyuki
Y
Watanabe
Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan. shigeo@me.es.osaka-u.ac.jp.
Shigeo
S
Wada
D000783:Aneurysm / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology*; D002536:Cerebral Arteries / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003198:Computer Simulation; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D057446:Hydrodynamics; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008955:Models, Cardiovascular; D013314:Stress, Mechanical
D003287:Contrast Media
Cerebral aneurysm; Computational fluid dynamics; Measurement integrated simulation; Phase-contrast magnetic resonance imaging; Pressure boundary condition