A Proof of Concept of a Non-Invasive Image-Based Material Characterization Method for Enhanced Patient-Specific Computational Modeling

Abstract

Computational models of cardiovascular structures rely on their accurate mechanical characterization. A validated method able to infer the material properties of patientspecific large vessels is currently lacking. The aim of the present study is to present a technique starting from the flow-area (QA) method to retrieve basic material properties from magnetic resonance (MR) imaging. MethodsThe proposed method was developed and tested, first, in silico and then in vitro. In silico, fluid-structure interaction (FSI) simulations of flow within a deformable pipe were run with varying elastic modules (E) between 0.5 and 32 MPa. The proposed QA-based formulation was assessed and modified based on the FSI results to retrieve E values. In vitro, a compliant phantom connected to a mock circulatory system was tested within MR scanning. Images of the phantom were acquired and post-processed according to the modified formulation to infer E of the phantom. Results of in vitro imaging assessment were verified against standard tensile test. ResultsIn silico results from FSI simulations were used to derive the correction factor to the original formulation based on the geometrical and material characteristics. In vitro, the modified QA-based equation estimated an average E = 0.51 MPa, 2% different from the E derived from tensile tests (i.e. E = 0.50 MPa). ConclusionThis study presented promising results of an indirect and non-invasive method to establish elastic properties from solely MR images data, suggesting a potential image-based mechanical characterization of large blood vessels.

On the Role and Effects of Uncertainties in Cardiovascular in silico Analyses

“…While the FSI and CFD RBF manifested no significant difference in terms of WSS distribution, the CFD RBF method did not require any hypothesis on the material constitutive model. For this reason, no strong assumption and indirect in vivo measures was introduced ( 27 , 28 ). The CFD RBF method was computed exclusively on the basis of the segmentation of the cardiac phases.…”

Fully-Coupled FSI Computational Analyses in the Ascending Thoracic Aorta Using Patient-Specific Conditions and Anisotropic Material Properties

“…Hemodynamics and the interactions between the blood and the aortic wall are ones of these causes and computational approaches aim at making patient-specific predictions of these factors and of their role in aTAA rupture (Capellini et al, 2020 ; De Nisco et al, 2020 ). The current trend is personalized medicine, where patient-specific parameters are introduced at different levels including morphology, fluid dynamics conditions and tissue mechanics (Condemi et al, 2017 ; Boccadifuoco et al, 2018a ; Fanni et al, 2020 ).…”

Development and Realization of an Experimental Bench Test for Synchronized Small Angle Light Scattering and Biaxial Traction Analysis of Tissues

“…The consequences of microstructural modifications on the material mechanics are often times underlined in different works [38,39]. For example, Robitaille et al adopted the SALS technique for microstructural characterization of cornea tissues under mechanical strain [40].…”