Numerical simulation in the abdominal aorta and the visceral arteries with or without stenosis based on 2D PCMRI. (18th January 2022)

• Record Type: Journal Article
• Authors: Peng, Chen; Liu, Junzhen; He, Wei; Qin, Wang; Yuan, Tong; Kan, Yuanqing; Wang, Keqiang; Wang, Shengzhang; Shi, Yun
• Is Part Of: International journal for numerical methods in biomedical engineering. Volume 38:Number 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-18
• Subjects: abdominal aorta -- boundary conditions -- computational fluid dynamics -- phase‐contrast magnetic resonance imaging -- visceral arterial stenosis; Biomedical engineering -- Periodicals; Imaging systems in medicine -- Periodicals; Numerical analysis -- Periodicals; Engineering mathematics -- Periodicals; 610.28
• DOI: 10.1002/cnm.3569
• Languages: English
• ISSNs: 2040-7939

Abstract

Abstract: It is important to obtain accurate boundary conditions (BCs) in hemodynamic simulations. This article aimed to improve the accuracy of BCs in computational fluid dynamics (CFD) simulation and analyze the differences in hemodynamics between healthy volunteers and patients with visceral arterial stenosis (VAS). The geometric models of seven cases were reconstructed using the magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging data. The physiological flow waveforms obtained from 2D Phase Contrast Magnetic Resonance Imaging (PCMRI) were imposed on the aortic inlet and the visceral arteries' outlets. The individualized RCR values of the three‐element Windkessel model were imposed on the aortic outlet. CFD simulations were run in the open‐source software: svSolver. Two specific time points were selected to compare the hemodynamics of healthy volunteers and patients with VAS. The results suggested that blood in the stenotic visceral arteries flowed at high speed throughout the cardiac cycle. The low pressure is distributed at stenotic lesions. The wall shear stress (WSS) reached 4 Pa near stenotic locations. The low time average wall shear stress (TAWSS), high oscillatory shear index (OSI), and high relative residence time (RRT) concentrated in the abdominal aorta. Besides, the ratios of the areas with low TAWSS, high OSI, and high RRT to the computational domain were higher in patients with VAS than which in the healthy volunteers. The individualized BCs were used for hemodynamic simulations and results suggest that patients with stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta. Abstract : The boundary conditions settings are important in hemodynamic simulations. Based on the 2D phase contrast magnetic resonance imaging, realistic physiological flow waveforms tested in vivo were imposed on the abdominal aortic inlet and the visceral arteries' outlets. The individualized RCR values were calculated and imposed on the abdominal aortic outlet. Hemodynamic simulation results suggested that patients with visceral arterial stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta.