Hemodynamic Assessment of Cerebral Aneurysms Using Computational Fluid Dynamics (CFD) Involving the Establishment of Non-Newtonian Fluid Properties

Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurysm wall and large swirling flow structures. A new finding was that all cases showed an increase in kinetic energy from the first time point to the second, and this change in kinetic energy seems correlated to the change in aneurysm volume.

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Computational fluid dynamics (CFD) using porous media modeling predicts recurrence after coiling of cerebral aneurysms

PLoS ONE ◽

10.1371/journal.pone.0190222 ◽

2017 ◽

Vol 12 (12) ◽

pp. e0190222 ◽

Cited By ~ 7

Author(s):

Yasuyuki Umeda ◽

Fujimaro Ishida ◽

Masanori Tsuji ◽

Kazuhiro Furukawa ◽

Masato Shiba ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Porous Media ◽

Cerebral Aneurysms ◽

Computational Fluid Dynamics Cfd

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Computational Fluid Dynamics for Cerebral Aneurysms in Clinical Settings

Acta Neurochirurgica Supplement - Trends in Cerebrovascular Surgery and Interventions ◽

10.1007/978-3-030-63453-7_4 ◽

2021 ◽

pp. 27-32

Author(s):

Fujimaro Ishida ◽

Masanori Tsuji ◽

Satoru Tanioka ◽

Katsuhiro Tanaka ◽

Shinichi Yoshimura ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Cerebral Aneurysms ◽

Patient Specific ◽

Clinical Settings ◽

Geometry Model ◽

Aneurysm Wall ◽

3D Ct Angiography ◽

Specific Geometry ◽

Computational Fluid Dynamics Cfd

AbstractHemodynamics is thought to play an important role in the pathogenesis of cerebral aneurysms and recent development of computer technology makes it possible to simulate blood flow using high-resolution 3D images within several hours. A lot of studies of computational fluid dynamics (CFD) for cerebral aneurysms were reported; therefore, application of CFD for cerebral aneurysms in clinical settings is reviewed in this article.CFD for cerebral aneurysms using a patient-specific geometry model was first reported in 2003 and it has been revealing that hemodynamics brings a certain contribution to understanding aneurysm pathology, including initiation, growth and rupture. Based on the knowledge of the state-of-the-art techniques, this review treats the decision-making process for using CFD in several clinical settings. We introduce our CFD procedure using digital imaging and communication in medicine (DICOM) datasets of 3D CT angiography or 3D rotational angiography. In addition, we review rupture status, hyperplastic remodeling of aneurysm wall, and recurrence of coiled aneurysms using the hemodynamic parameters such as wall shear stress (WSS), oscillatory shear index (OSI), aneurysmal inflow rate coefficient (AIRC), and residual flow volume (RFV).

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Effects of Arterial Geometry on Inflow Rate Into Cerebral Aneurysms on Curved Arteries

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176556 ◽

2007 ◽

Author(s):

Yohsuke Imai ◽

Kodai Sato ◽

Takuji Ishikawa ◽

Takami Yamaguchi

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Mass Transport ◽

Cerebral Aneurysms ◽

Inflow Rate ◽

Atherosclerotic Lesions ◽

Computational Fluid Dynamics Cfd

Pathobiological studies have demonstrated that atherosclerotic lesions have been found on the wall of saccular cerebral aneurysms [1]. We propose a hypothesis that some of these aneurysms are prevented from rupturing due to the atherosclerotic lesions. It has been presented that mass transport of biochemical species such as LDL and ATP, has some important roles in the development of atherosclerosis. A variety of Computational Fluid Dynamics (CFD) studies of the mass transport has been performed for arteries [2, 3], few studies have however, done for aneurysms.

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Computational fluid dynamics (CFD) analysis using porous media modeling predicts angiographic occlusion status after coiling of unruptured cerebral aneurysms—Preliminary study

Journal of Neuroendovascular Therapy ◽

10.5797/jnet.or.2014-0035 ◽

2015 ◽

Vol 9 (2) ◽

pp. 69-77 ◽

Cited By ~ 6

Author(s):

Yasuyuki UMEDA ◽

Fujimaro ISHIDA ◽

Masanori TSUJI ◽

Kazuhiro FURUKAWA ◽

Takanori SANO ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Porous Media ◽

Cerebral Aneurysms ◽

Cfd Analysis ◽

Computational Fluid Dynamics Cfd ◽

Preliminary Study ◽

Unruptured Cerebral Aneurysms

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4D-CT angiography versus 3D-rotational angiography as the imaging modality for computational fluid dynamics of cerebral aneurysms

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2019-015389 ◽

2019 ◽

Vol 12 (6) ◽

pp. 626-630 ◽

Cited By ~ 5

Author(s):

Nicole M Cancelliere ◽

Mehdi Najafi ◽

Olivier Brina ◽

Pierre Bouillot ◽

Maria I Vargas ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Ct Angiography ◽

Cerebral Aneurysms ◽

Patient Specific ◽

Parent Artery ◽

Rotational Angiography ◽

Specific Flow ◽

Flow Rates ◽

Hemodynamic Assessment

Background and purposeComputational fluid dynamics (CFD) can provide valuable information regarding intracranial hemodynamics. Patient-specific models can be segmented from various imaging modalities, which may influence the geometric output and thus hemodynamic results. This study aims to compare CFD results from aneurysm models segmented from three-dimensional rotational angiography (3D-RA) versus novel four-dimensional CT angiography (4D-CTA).MethodsFourteen patients with 16 cerebral aneurysms underwent novel 4D-CTA followed by 3D-RA. Endoluminal geometries were segmented from each modality using an identical workflow, blinded to the other modality, to produce 28 'original' models. Each was then minimally edited a second time to match length of branches, producing 28 additional 'matched' models. CFD simulations were performed using estimated flow rates for 'original' models (representing real-world experience) and patient-specific flow rates from 4D-CTA for 'matched' models (to control for influence of modality alone).ResultsOverall, geometric and hemodynamic results were consistent between models segmented from 3D-RA and 4D-CTA, with correlations improving after matching to control for operator-introduced variability. Despite smaller 4D-CTA parent artery diameters (3.49±0.97 mm vs 3.78±0.92 mm for 3D-RA; p=0.005) and sac volumes (157 (37–750 mm3) vs 173 (53–770 mm3) for 3D-RA; p=0.0002), sac averages of time-averaged wall shear stress (TAWSS), oscillatory shear (OSI), and high frequency fluctuations (measured by spectral power index, SPI) were well correlated between 3D-RA and 4D-CTA 'matched' control models (TAWSS, R2=0.91; OSI, R2=0.79; SPI, R2=0.90).ConclusionsOur study shows that CFD performed using 4D-CTA models produces reliable geometric and hemodynamic information in the intracranial circulation. 4D-CTA may be considered as a follow-up imaging tool for hemodynamic assessment of cerebral aneurysms.

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