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Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis./
Author:	Varble, Nicole.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
Description:	168 p.
Notes:	Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.
Contained By:	Dissertation Abstracts International79-08B(E).
Subject:	Mechanical engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10744662
ISBN:	9780355679885

Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis.
Varble, Nicole.

Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 168 p.

Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.

Thesis (Ph.D.)--State University of New York at Buffalo, 2018.

Intracranial aneurysms (IAs) are a cerebrovascular pathology present in 3--5% of the population. Aneurysm rupture leads to subarachnoid hemorrhage, a devastating event that is associated with high rates of mortality and morbidity. However, because the rupture rate is low and the risk of surgical complications can be significant, the decision of whether or not to treat an unruptured IA is difficult. Currently, IA size is the most commonly used metric for assessing rupture risk. However, a high frequency of small aneurysms are known to rupture and clinical presentations suggest that small and large IAs could have different phenotypes. Thus, objective guidelines to determine the relative risk of rupture are warranted.

ISBN: 9780355679885Subjects--Topical Terms:

557493
Mechanical engineering.

Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis.
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245 1 0 $a Application of Patient Image-Based CFD to Intracranial Aneurysm Rupture Risk Analysis.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 168 p.
500 $a Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.
500 $a Adviser: Hui Meng.
502 $a Thesis (Ph.D.)--State University of New York at Buffalo, 2018.
520 $a Intracranial aneurysms (IAs) are a cerebrovascular pathology present in 3--5% of the population. Aneurysm rupture leads to subarachnoid hemorrhage, a devastating event that is associated with high rates of mortality and morbidity. However, because the rupture rate is low and the risk of surgical complications can be significant, the decision of whether or not to treat an unruptured IA is difficult. Currently, IA size is the most commonly used metric for assessing rupture risk. However, a high frequency of small aneurysms are known to rupture and clinical presentations suggest that small and large IAs could have different phenotypes. Thus, objective guidelines to determine the relative risk of rupture are warranted.
520 $a Researchers have investigated aneurysmal characteristics associated with IA pathophysiology and found that intra-aneurysmal hemodynamics play a significant role in IA remodeling, growth and rupture. Statistical studies using image-based computational fluid dynamics (CFD) have found that time-averaged fluid shear stresses on the aneurysm wall, as well as certain morphological features, are significantly associated with IA rupture status. However, such studies cannot elucidate the underlying flow physics and, furthermore, do not consider the potential difference between small and large IAs. Therefore, the aims of this work are two-fold: 1) investigate the flow physics in complex aneurysm geometries from temporal and spatial perspectives, especially as it relates to the fate of the IAs, and 2) determine if small and large IAs have different characteristics that discriminate rupture.
520 $a First, two studies were performed to investigate the temporal and spatial flow physics of IAs and their relationship to rupture. In the first study, we analyzed temporal flow instabilities in 56 middle cerebral artery aneurysms (12 ruptured) by transient, constant inflow, high-resolution computational fluid dynamics simulations. In the second study, we objectively quantified the degree of the aneurysmal region occupied by vortex structures in 204 patient IAs (56 ruptured) based on the Q-criterion definition of a vortex. Flow instabilities and vortex structures were objectively quantified and the association to IA rupture and previously developed predictors of rupture was investigated.
520 $a In the third study, we determined if small and large IAs have different characteristics that discriminate rupture. From 413 retrospectively collected IAs (training cohort; 102 ruptured) we determine a size cutoff to dichotomize the IA population into small and large IAs by hierarchal cluster analysis. Then, to build rupture discrimination models for small IAs, large IAs, and an aggregation of all IAs, multivariate logistic regression was applied. These 3 models were validated in a second, independently collected cohort of 129 IAs (testing cohort; 14 ruptured).
520 $a The results of these studies demonstrated the importance choosing the appropriate CFD solver settings and the relevance of flow dynamics near the wall, rather than the volume. Additionally, we determined that 5mm best separated small and large IAs and that they have different hemodynamic and clinical, but not morphologic, rupture discriminants. We demonstrated that size-dichotomized rupture discrimination models performed better than the aggregate model.
520 $a Lastly, included in this work are two studies to support and complement previous findings. The first supplementary study explains the potential difference rupture propensities at different anatomical locations in the Circle of Willis by comparing morphological and hemodynamic characteristics of 311 unruptured IAs at different locations. We found that internal carotid artery aneurysms may be subjected to less rupture-prone morphologic and hemodynamic characteristics compared to other locations. In the second supplementary study, we demonstrated the potential correlation between previously developed morphologic and hemodynamic risk prediction models to IA growth. Together, these studies demonstrate the complex and multifaceted nature of IA rupture.
590 $a School code: 0656.
650 4 $a Mechanical engineering. $3 557493
650 4 $a Engineering. $3 561152
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773 0 $t Dissertation Abstracts International $g 79-08B(E).
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791 $a Ph.D.
792 $a 2018
793 $a English
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