Blood Flow in Cerebral Aneurysms: Comparison of Phase Contrast Magnetic Resonance and Computational Fluid Dynamics - Preliminary Experience

Karmonik, Christof; Klucznik, Richard P.; Benndorf, Goetz

doi:10.1055/s-2008-1027135

Cited by 37 publications

(20 citation statements)

References 9 publications

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“…For all three aneurysms, velocity patterns contained regions with positive and negative flow velocities corresponding to the well-known rotational or swirling blood motion as the primary motion of flow in this kind of aneurysms. In all cases, the velocity patterns measured with 2D pcMRI compared favorably with the ones calculated with CFD thereby indicating the general validity of the simulations utilized in this study for visualizing and quantifying cerebral aneurysm hemodynamics (Karmonik et al 2008b). Advances in rapid prototyping techniques now allow conducting this kind of validation studies with accurate 3D replica and flow loops (Fig.…”

Section: Validation Approachessupporting

confidence: 55%

Computational Fluid Dynamics and Cerebral Aneurysms

Karmonik

Britz

2014

PanVascular Medicine

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Advances in computational techniques mitigated by faster computer hardware and improvements in software algorithms have increased interest in exploring their potential value for application in clinical research. Information derived from medical image data can be utilized to create computational models for simulating hemodynamics in cerebral aneurysms. In this chapter, we review the principles of computational fluid dynamics (CFD) aimed at this application and discuss results from selected studies which focused on developing CFD techniques for applications in clinical research. Validation studies comparing measurements with simulation results have demonstrated that this approach is viable and thereby encourage further development and refinement. They have also shown that multidisciplinary collaborative teams involving clinicians and clinical and basic scientists are needed to lead these exciting translational research efforts to fruition. Glossary of Terms AneurysmA focal balloon-like extension or bulge in a blood vessel. Cerebral aneurysms affect arteries of the brain, while aortic aneurysms are located in the aorta. Computational fluid dynamicsA subspecialty of the large field of fluid mechanics in which numerical algorithms are developed and used with high-performance computers to solve problems related to fluid flow. Computed tomography angiographyA medical imaging technology where the computational analysis of X-rays is combined with the administration of a contrast agent to create three-dimensional visualization of blood vessels and the heart. Digital subtraction angiography A medical imaging technique based on fluoroscopy, where images acquired before and after the administration of a contrast agent are subtracted to obtain very accurate visualizations of blood vessels with high spatial resolution. Endothelium A thin layer of cells lining the inner surface of blood vessels. Endothelial cells have been shown to have receptors for sensing the wall shear stress created by the flowing blood. Endovascular treatmentA surgical technique to treat selected vascular pathologies in the brain and other parts of the body through a catheter and attached medical devices which are navigated to the treatment site within the blood vessels.*Email: ckarmonik@tmhs.org *Email: ckarmonik@houstonmethodist.org PanVascular Medicine DOI 10.1007/978-3-642-37393-0_33-1 # Springer-Verlag Berlin Heidelberg 2014Page 1 of 13 HemodynamicsThe field which aims at developing a better understanding of how blood flows in blood vessels by establishing the corresponding physical laws and the governing equations of motion. Magnetic resonance imagingA medical imaging technology which uses strong magnetic fields and radio-frequency pulses to probe and visualize anatomy and physiology both in health and disease. Mesh generationThe digital separation of an often irregularly shaped volume into small regular volume elements, for instance, tetrahedra, pyramids, or hexahedra. This is a prerequisite for applying computational simulations which rely ...

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Section: Validation Approachessupporting

confidence: 55%

Computational Fluid Dynamics and Cerebral Aneurysms

Karmonik

Britz

2014

PanVascular Medicine

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“…16 The QMRA software has automated the placement of a perpendicular imaging plane and the selection of the appropriate VENC based on the actual flow in the vessel under study. To date, this technique has been used to guide patient management in cerebral revascularization surgery [17][18][19][20] ; assess intracranial and extracranial vessel stenosis pre-and poststent placement 21 ; measure blood flow in cerebral aneurysms 22 ; evaluate subclavian steal syndrome 23 ; assess collateral volume flow in large-vessel cerebrovascular disease 24 ; and predict outcomes of balloon-occlusion testing. 20 Although in vitro validation of QMRA has been performed by using flow phantoms, 16 in vivo evaluation of clinically relevant cerebrovascular flows, in conjunction with progressive arterial stenosis, has not been previously described.…”

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confidence: 99%

In Vivo Evaluation of Quantitative MR Angiography in a Canine Carotid Artery Stenosis Model

Calderon-Arnulphi¹,

Amin‐Hanjani²,

Alaraj³

et al. 2011

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE: Large-vessel cerebral blood flow quantification has emerged as a potential predictor of stroke risk. QMRA uses phase-contrast techniques to noninvasively measure vessel flows. To evaluate the in vivo accuracy of QMRA for measuring the effects of progressive arterial stenosis, we compared this technique with invasive flow measurements from a sonographic transit-time flow probe in a canine model.

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“…This technique has been shown to be an accurate and reliable method for velocity quantification in cervical and intracranial vessels in various cerebrovascular conditions, 11,12,[30][31][32][33] such as aneurysmal disease. 34 It is highly correlated to Laser Doppler Velocimetry as reference method and endovascular Doppler techniques for flow quantifications, especially in large arteries as in ICA. [35][36][37] This noninvasive and nonirradiating technique is widely available in clinical practice.…”

Section: Discussionmentioning

confidence: 99%

MR Derived Volumetric Flow Rate Waveforms of Internal Carotid Artery in Patients Treated for Unruptured Intracranial Aneurysms by Flow Diversion Technique

Boudjeltia

Corredor-Jerez

Bars

et al. 2015

J Cereb Blood Flow Metab

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Little is known about the hemodynamic disturbances induced by the cerebral aneurysms in the parent artery and the effect of flow diverter stents (FDS) on these latter. A better understanding of the aneurysm-parent vessel complex relationship may aid our understanding of this disease and to optimize its treatment. The ability of volumetric flow rate (VFR) waveform to reflect the arterial compliance modifications is well known. By analyzing the VFR waveform and the pulsatility in the parent vessel, this study aimed to test the hypotheses that (1) intracranial aneurysms might disrupt the blood flow of the parent vessel and (2) the treatment by FDS might have measurable corrective effect on these changes. Ten patients followed for unruptured intracranial aneurysms treated by FDS and ten healthy volunteers as control group were included in this study. Two-dimensional quantitative phase-contrast magnetic resonance imaging (MRI) was performed on each patient on the ICA artery upstream and downstream to the aneurysm, and on each volunteer at similar locations. The aneurysms altered significantly the parent vessel pulsatility and this effect was correlated to their volume. The aneurysms treatment by FDS allowed for the restoration of a normally modulated flow and pulsatility correction in the parent vessel.

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Blood Flow in Cerebral Aneurysms: Comparison of Phase Contrast Magnetic Resonance and Computational Fluid Dynamics - Preliminary Experience

Cited by 37 publications

References 9 publications

Computational Fluid Dynamics and Cerebral Aneurysms

Computational Fluid Dynamics and Cerebral Aneurysms

In Vivo Evaluation of Quantitative MR Angiography in a Canine Carotid Artery Stenosis Model

MR Derived Volumetric Flow Rate Waveforms of Internal Carotid Artery in Patients Treated for Unruptured Intracranial Aneurysms by Flow Diversion Technique

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