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Follow-up Study of the Intravascular Hemodynamics of the Aneurysm of the Abdominal Aorta. Integration of CFD and Complex Networks theory

Daniela Barberis

Follow-up Study of the Intravascular Hemodynamics of the Aneurysm of the Abdominal Aorta. Integration of CFD and Complex Networks theory.

Rel. Umberto Morbiducci, Diego Gallo, Karol Calo'. Politecnico di Torino, Corso di laurea magistrale in Ingegneria Biomedica, 2020


The ample evidence that hemodynamics is involved in the local onset and progression of vascular disease, makes the study of cardiovascular flows of wide interest. To date, the large amount of hemodynamic data has been processed through conventional quantification and visualization paradigms, which permit only partially to exploit all the information regarding how blood flow patterns evolve and correlate in complex vascular geometries and during the progression of a pathological condition. In this study, with the intent to uncover and highlight the spatiotemporal evolution and the level of organization of critical blood flow patterns, an innovative approach is proposed combining correlation-based analysis and complex networks (CNs) theory with computational hemodynamics. This approach is applied for the first time to patient-specific abdominal aortic aneurysm (AAA) models: geometry reconstruction is performed from CT scans at two different time points (namely baseline and follow-up), and unsteady-state large eddy simulations (LES) are carried out. Correlation-based networks are constructed starting from nodal time-histories of three fluid mechanics quantities of physiological significance, respectively (1) the blood velocity vector axial component locally aligned with the main forward flow direction, (2) the blood velocity vector secondary component acting orthogonally to the vessel axis and (3) the kinetic helicity density. CNs metric are applied to quantify the compactness/dispersion, in terms of spatial scales, of correlated intravascular hemodynamic features characterizing AAA models. Our main findings show that the aneurysmal dilation disrupts the network topological connections between axial flow structures, reducing also their anatomical sphere of influence. On the other hand, connections in secondary velocity- and helicity- based networks are less “aneurysm-sensitive”, however both confirm the flow arrangement in counter-rotating structures. The present study suggests the potential of the recently-introduced complex networks theory as an innovative method to investigate vascular hemodynamics in diseased vessel, providing more insight into its role in vascular physiopathology.

Relators: Umberto Morbiducci, Diego Gallo, Karol Calo'
Academic year: 2020/21
Publication type: Electronic
Number of Pages: 126
Additional Information: Tesi secretata. Full text non presente
Corso di laurea: Corso di laurea magistrale in Ingegneria Biomedica
Classe di laurea: New organization > Master science > LM-21 - BIOMEDICAL ENGINEERING
Aziende collaboratrici: UNSPECIFIED
URI: http://webthesis.biblio.polito.it/id/eprint/16981
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