Vessels-Cut: A Graph Based Approach to Patient-Specific Carotid Arteries Modeling

2009 ◽  
pp. 1-12 ◽  
Author(s):  
Moti Freiman ◽  
Noah Broide ◽  
Miriam Natanzon ◽  
Einav Nammer ◽  
Ofek Shilon ◽  
...  
Keyword(s):  
Carotid Arteries ◽  
Patient Specific

scholarly journals Effects of the Haemodynamic Stimulus on the Location of Carotid Plaques Based on a Patient-Specific Mechanobiological Plaque Atheroma Formation Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Patricia Hernández-López ◽  
Myriam Cilla ◽  
Miguel Martínez ◽  
Estefanía Peña
Keyword(s):  
Carotid Arteries ◽  
Stokes Equations ◽  
Shape Index ◽  
Mechanical Stimulus ◽  
Diffusion Reaction ◽  
Navier Stokes ◽  
Patient Specific ◽  
Clinical Images ◽  
Navier Stokes Equations ◽  
Using Data

In this work, we propose a mechanobiological atheroma growth model modulated by a new haemodynamic stimulus. To test this model, we analyse the development of atheroma plaques in patient-specific bifurcations of carotid arteries for a total time of 30 years. In particular, eight geometries (left or right carotid arteries) were segmented from clinical images and compared with the solutions obtained computationally to validate the model. The influence of some haemodynamical stimuli on the location and size of plaques is also studied. Plaques predicted by the mechanobiological models using the time average wall shear stress (TAWSS), the oscillatory shear index (OSI) and a new index proposed in this work are compared. The new index predicts the shape index of the endothelial cells as a combination of TAWSS and OSI values and was fitted using data from the literature. The mechanobiological model represents an evolution of the one previously proposed by the authors. This model uses Navier-Stokes equations to simulate blood flow along the lumen in the transient mode. It also employs Darcy's law and Kedem-Katchalsky equations for plasma and substance flow across the endothelium using the three-pore model. The mass balances of all the substances that have been considered in the model are implemented by convection-diffusion-reaction equations, and finally the growth of the plaques has been computed. The results show that by using the new mechanical stimulus proposed in this study, prediction of plaques is, in most cases, better than only using TAWSS or OSI with a minimal and maximal errors on stenosis ratio of 2.77 and 32.89 %, respectively. However, there are a few geometries in which haemodynamics cannot predict the location of plaques, and other biological or genetic factors would be more relevant than haemodynamics. In particular, the model predicts correctly eleven of the fourteen plaques presented in all the geometries considered. Additionally, a healthy geometry has been computed to check that plaque is not developed with the model in this case.

Computational Fluid Dynamics of Carotid Arteries After Carotid Endarterectomy or Carotid Artery Stenting Based on Postoperative Patient-Specific Computed Tomography Angiography and Ultrasound Flow Data

Neurosurgery ◽  
2011 ◽  
Vol 68 (4) ◽  
pp. 1096-1101 ◽  
Author(s):  
Hitoshi Hayase ◽  
Koji Tokunaga ◽  
Toshio Nakayama ◽  
Kenji Sugiu ◽  
Ayumi Nishida ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computed Tomography ◽  
Computational Fluid Dynamics ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Carotid Arteries ◽  
Internal Carotid ◽  
Patient Specific ◽  
Flow Data ◽  
Simulation Results

Abstract BACKGROUND: There are significant differences in the postoperative morphological and hemodynamic conditions of the carotid arteries between carotid artery stenting (CAS) and endarterectomy (CEA). OBJECTIVE: To compare the postoperative rheological conditions after CAS with those after CEA with patch angioplasty (patch CEA) through the use of computational fluid dynamics (CFD) based on patient-specific data. METHODS: The rheological conditions in the carotid arteries were simulated in 2 patients after CAS and in 2 patients after patch CEA by CFD calculations. Three-dimensional reconstruction of the carotid arteries was performed with the images obtained with computed tomography angiography. The streamlines and wall shear stress (WSS) were calculated by a supercomputer. Adequate boundary conditions were determined by comparing the simulation results with ultrasound flow data. RESULTS: CFD was successfully calculated for all patients. The differences between the flow velocities of ultrasound data and those of the simulation results were limited. In the streamline analysis, the maximum flow velocities in the internal carotid artery after patch CEA were around two-thirds of those after CAS. Rotational slow flow was observed in the internal carotid artery bulb after patch CEA. WSS analysis found regional low WSS near the outer wall of the bulb. High WSS was observed at the distal end of the arteriotomy after patch CEA and at the residual stenosis after CAS. CONCLUSION: CFD of postoperative carotid arteries disclosed the differences in streamlines and WSS between CAS and patch CEA. CFD may allow us to obtain adequate rheological conditions conducive to achieving the best clinical results.

The importance of blood rheology in patient-specific computational fluid dynamics simulation of stenotic carotid arteries

2020 ◽  
Vol 19 (5) ◽  
pp. 1477-1490 ◽  
Author(s):  
Jessica Benitez Mendieta ◽  
Davide Fontanarosa ◽  
Jiaqiu Wang ◽  
Phani Kumari Paritala ◽  
Tim McGahan ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Carotid Arteries ◽  
Blood Rheology ◽  
Dynamics Simulation ◽  
Patient Specific ◽  
Computational Fluid Dynamics Simulation

Computational analysis to predict the effect of pre-bifurcation stenosis on the hemodynamics of the internal and external carotid arteries

2020 ◽  
Vol 14 (3) ◽  
pp. 7029-7039
Author(s):  
Hugo Bouteloup ◽  
Johann Guimaraes de Oliveira Marinho ◽  
Surapong Chatpun ◽  
Daniel M. Espino
Keyword(s):  
Carotid Artery ◽  
Common Carotid Artery ◽  
Carotid Arteries ◽  
Three Dimensional ◽  
Patient Specific ◽  
External Carotid ◽  
Shear Stresses ◽  
Flow Profile ◽  
Velocity Flow ◽  
The Common

This study assessed the hemodynamics of a patient-specific multiple stenosed common carotid artery including its bifurcation into internal and external carotid arteries; ICA and ECA, respectively. A three-dimensional computational model of the common carotid artery was reconstructed using a process of segmentation. Computational fluid dynamics was applied with the assumption that blood is Newtonian and incompressible under pulsatile conditions through the stenotic artery and subsequent bifurcation. Blood was modelled as ‘normal’ and ‘hyperglycaemic’. A region of large recirculation was found to form at bifurcation. The asymmetric velocity flow profile through the ICA was evident through the cardiac cycle with higher velocity at the inner walls of ICA. Hyperglycaemia was found to increase wall shear stresses on the carotid artery and reduce the blood velocity by as much as 4 times in ECA. In conclusion, hemodynamics in ICA and ECA are not equally affected by stenosis, with hyperglycaemic blood potentially providing additional complications to the clinical case. 

Patient-Specific Modeling of Atherosclerotic Carotid Arteries From Multi-Modality Image Data

2003 ◽  
Author(s):  
Juan R. Cebral ◽  
Christopher Putman ◽  
Richard Pergolizzi ◽  
James E. Burgess
Keyword(s):  
Shear Stress ◽  
Magnetic Resonance ◽  
Wall Shear Stress ◽  
Carotid Arteries ◽  
Stokes Equations ◽  
Duplex Ultrasound ◽  
Flow Patterns ◽  
Patient Specific ◽  
Detailed Knowledge ◽  
Wall Shear

Estimation of the wall shear stress distribution in stenotic carotid arteries is important for assessing risk of stroke. Since there are no reliable experimental methods to determine wall shear stress distributions, realistic patient-specific computational fluid dynamics models are constructed from medical images. Anatomical and physiologic data are obtained from multiple image modalities including 3D rotational angiography, contrast-enhanced magnetic resonance angiography, carotid duplex ultrasound and phase-contrast magnetic resonance. These images are used to construct patient-specific finite element grids and to solve the incompressible Navier-Stokes equations under physiological pulsatile flow conditions. The detailed knowledge of the carotid hemodynamics derived from these models can be used to enhance our understanding of the relationship between flow patterns and symptoms, and ultimately risk of stroke. This methodology can also be used to correllate flow patterns with the outcome of endovascular procedures such as angioplasty and stenting.

MRI Based Quantification of Outflow Boundary Conditions for Computational Fluid Dynamics of Stenosed Human Carotid Arteries

2010 ◽  
Author(s):  
Harald C. Groen ◽  
Lenette Simons ◽  
E. Marielle H. Bosboom ◽  
Frans van de Vosse ◽  
Anton F. W. van der Steen ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Carotid Arteries ◽  
Patient Specific ◽  
Murray's Law ◽  
Murray’S Law ◽  
Outflow Boundary Conditions ◽  
Outflow Boundary ◽  
Human Carotid

Many studies have been performed to investigate the contribution of wall shear stress (WSS) to pathophysiological processes related to atherosclerosis (Groen, et al., 2007; Kaazempur-Mofrad, et al., 2004; Ku, et al., 1985). To investigate these relationships in stenosed human carotid arteries, accurate assessment of WSS is required. WSS can be calculated in vivo by coupling medical imaging and computational fluid dynamics (CFD). However, often patient specific in- and outflow information is unavailable. Therefore flow through the common (CCA), internal (ICA) and external (ECA) carotid artery needs to be estimated. Murray’s law (Murray, 1926) is often used for that purpose, but it is unclear whether this law holds for stenosed arteries. The goal of this study was to determine outflow boundary conditions for WSS calculations in stenosed carotid bifurcations. Therefore we first quantified the flow (Q) in carotid arteries with different degrees of area stenosis using phase-contrast MRI and determined an empirical relation between outflow-ratios and degree of area stenosis. Secondly we compared the estimated flow ratio based on Murray’s law to the ones measured by MRI. Finally we analyzed the influence of the outflow conditions on the calculated WSS using CFD.

Sign in / Sign up

Export Citation Format

Share Document