scholarly journals 4D phase contrast MRI in intracranial aneurysms: a comparison with patient-specific computational fluid dynamics with temporal and spatial velocity boundary conditions as measured with 3D phase contrast MRI

2012 ◽  
Vol 14 (S1) ◽  
Author(s):  
Pim van Ooij ◽  
Joppe Schneiders ◽  
Henk Marquering ◽  
Charles B Majoie ◽  
Ed vanBavel ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Intracranial Aneurysms ◽  
Phase Contrast ◽  
Patient Specific ◽  
Phase Contrast Mri ◽  
Spatial Velocity ◽  
Temporal And Spatial

scholarly journals 3D Cine Phase-Contrast MRI at 3T in Intracranial Aneurysms Compared with Patient-Specific Computational Fluid Dynamics

2013 ◽  
Vol 34 (9) ◽  
pp. 1785-1791 ◽  
Author(s):  
P. van Ooij ◽  
J.J. Schneiders ◽  
H.A. Marquering ◽  
C.B. Majoie ◽  
E. van Bavel ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Intracranial Aneurysms ◽  
Phase Contrast ◽  
Patient Specific ◽  
Phase Contrast Mri ◽  
Cine Phase Contrast

scholarly journals Comparison of hemodynamics of intracranial aneurysms between MR fluid dynamics using 3D cine phase-contrast MRI and MR-based computational fluid dynamics

2009 ◽  
Vol 52 (10) ◽  
pp. 913-920 ◽  
Author(s):  
Haruo Isoda ◽  
Yasuhide Ohkura ◽  
Takashi Kosugi ◽  
Masaya Hirano ◽  
Marcus T. Alley ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Intracranial Aneurysms ◽  
Phase Contrast ◽  
Phase Contrast Mri ◽  
Mr Fluid ◽  
Cine Phase Contrast

Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Philipp Berg ◽  
Daniel Stucht ◽  
Gábor Janiga ◽  
Oliver Beuing ◽  
Oliver Speck ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Magnetic Resonance ◽  
Boundary Conditions ◽  
Intracranial Aneurysms ◽  
Phase Contrast ◽  
Resonance Imaging ◽  
Phase Contrast Magnetic Resonance ◽  
Contrast Magnetic Resonance

Computational fluid dynamics (CFD) opens up multiple opportunities to investigate the hemodynamics of the human vascular system. However, due to numerous assumptions the acceptance of CFD among physicians is still limited in practice and validation through comparison is mandatory. Time-dependent quantitative phase-contrast magnetic resonance imaging PC-MRI measurements in a healthy volunteer and two intracranial aneurysms were carried out at 3 and 7 Tesla. Based on the acquired images, three-dimensional (3D) models of the aneurysms were reconstructed and used for the numerical simulations. Flow information from the MR measurements were applied as boundary conditions. The four-dimensional (4D) velocity fields obtained by CFD and MRI were qualitatively as well as quantitatively compared including cut planes and vector analyses. For all cases a high similarity of the velocity patterns was observed. Additionally, the quantitative analysis revealed a good agreement between CFD and MRI. Deviations were caused by minor differences between the reconstructed vessel models and the actual lumen. The comparisons between diastole and systole indicate that relative differences between MRI and CFD are intensified with increasing velocity. The findings of this study lead to the conclusion that CFD and MRI agree well in predicting intracranial velocities when realistic geometries and boundary conditions are provided. Due to the considerably higher temporal and spatial resolution of CFD compared to MRI, complex flow patterns can be further investigated in order to evaluate their role with respect to aneurysm formation or rupture. Nevertheless, special care is required regarding the vessel reconstruction since the geometry has a major impact on the subsequent numerical results.

scholarly journals Porous Media Computational Fluid Dynamics and the Role of the First Coil in the Embolization of Ruptured Intracranial Aneurysms

2021 ◽  
Vol 10 (7) ◽  
pp. 1348
Author(s):  
Karol Wiśniewski ◽  
Bartłomiej Tomasik ◽  
Zbigniew Tyfa ◽  
Piotr Reorowicz ◽  
Ernest Bobeff ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Porous Media ◽  
Packing Density ◽  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Patient Specific ◽  
Computational Fluid Dynamics Analysis ◽  
Ruptured Intracranial Aneurysms ◽  
Statistical Results

Background: The objective of our project was to identify a late recanalization predictor in ruptured intracranial aneurysms treated with coil embolization. This goal was achieved by means of a statistical analysis followed by a computational fluid dynamics (CFD) with porous media modelling approach. Porous media CFD simulated the hemodynamics within the aneurysmal dome after coiling. Methods: Firstly, a retrospective single center analysis of 66 aneurysmal subarachnoid hemorrhage patients was conducted. The authors assessed morphometric parameters, packing density, first coil volume packing density (1st VPD) and recanalization rate on digital subtraction angiograms (DSA). The effectiveness of initial endovascular treatment was visually determined using the modified Raymond–Roy classification directly after the embolization and in a 6- and 12-month follow-up DSA. In the next step, a comparison between porous media CFD analyses and our statistical results was performed. A geometry used during numerical simulations based on a patient-specific anatomy, where the aneurysm dome was modelled as a separate, porous domain. To evaluate hemodynamic changes, CFD was utilized for a control case (without any porosity) and for a wide range of porosities that resembled 1–30% of VPD. Numerical analyses were performed in Ansys CFX solver. Results: A multivariate analysis showed that 1st VPD affected the late recanalization rate (p < 0.001). Its value was significantly greater in all patients without recanalization (p < 0.001). Receiver operating characteristic curves governed by the univariate analysis showed that the model for late recanalization prediction based on 1st VPD (AUC 0.94 (95%CI: 0.86–1.00) is the most important predictor of late recanalization (p < 0.001). A cut-off point of 10.56% (sensitivity—0.722; specificity—0.979) was confirmed as optimal in a computational fluid dynamics analysis. The CFD results indicate that pressure at the aneurysm wall and residual flow volume (blood volume with mean fluid velocity > 0.01 m/s) within the aneurysmal dome tended to asymptotically decrease when VPD exceeded 10%. Conclusions: High 1st VPD decreases the late recanalization rate in ruptured intracranial aneurysms treated with coil embolization (according to our statistical results > 10.56%). We present an easy intraoperatively calculable predictor which has the potential to be used in clinical practice as a tip to improve clinical outcomes.

Comparative Computational Fluid Dynamics and Experimental Phase-Contrast MRI: Evaluations of In-Stent Restenosis

2004 ◽  
Author(s):  
Andrea D. Holton ◽  
Brigitta C. Brott ◽  
Edward G. Walsh ◽  
Ramakrishna Venugopalan ◽  
Alan M. Shih ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Phase Contrast ◽  
Imaging Modality ◽  
Metal Stents ◽  
Phase Contrast Mri ◽  
Peripheral Vasculature ◽  
Susceptibility Artifacts ◽  
Stent Restenosis ◽  
In Stent Restenosis

While angiography and other translesional catheter-based assessments of stented peripheral vasculature are currently used in clinical applications, a quantitative non-invasive imaging modality would improve the treatment of intermediate levels of in-stent restenosis (ISR). The use of magnetic resonance imaging (MRI), in metal stents has been limited due to magnetic susceptibility artifacts and radiofrequency shielding effects. However, MRI compatible materials such as nickel-titanium alloys used in stents have shown superior lumen visibility. In this study, we used phase contrast MRI in a flow phantom of three different geometries of stenosis: a) 90% axisymmetric, b) 75% axisymmetric and c) 50% asymmetric. The velocity distribution was obtained at 3 different locations inside the stent. This was compared with an equivalent computational fluid dynamics (CFD) model of the same stenotic geometries.

scholarly journals MR-based Computational Fluid Dynamics with Patient-specific Boundary Conditions for the Initiation of a Sidewall Aneurysm of a Basilar Artery

2015 ◽  
Vol 14 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Haruo ISODA ◽  
Yasuo TAKEHARA ◽  
Takashi KOSUGI ◽  
Masaki TERADA ◽  
Takehiro NAITO ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Basilar Artery ◽  
Patient Specific
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