Assessment of Thromboembolic Risk in the Left Atrium via 4D flow MRI and Computational Fluid Dynamics

Academic context: The research group at Mines Saint-Etienne leads major international research projects in the domain of soft tissue and fluid biomechanics in the cardiovascular system through a longstanding collaboration with the University Hospital in Saint-Etienne.

This project will be a collaboration between Mines Saint-Etienne and TU Vienna and will include a short research stay at TU Vienna. This project also includes collaboration with the University Hospital of Saint-Etienne and the Hospital Clinic in Barcelona.

Scientific context:  Interest in Left Atrium (LA) biomechanics has increased in recent years, as impaired atrial function is strongly linked to a higher risk of stroke. Atrial Fibrillation (AF) accounts for about one-third of all strokes, but roughly 20% remain of unknown origin, suggesting other LA-related mechanisms. Blood stagnation caused by altered LA wall mechanics (e.g., fibrosis) may promote thrombo-embolic events. Understanding the coupling between LA biomechanics, remodeling, and intra-atrial hemodynamics is therefore crucial for assessing atrial function and stroke risk. This project aims to develop stroke-risk biomarkers based on 4D flow MRI and computational fluid dynamics (CFD). While advanced imaging has improved LA characterization, modeling provides complementary predictive insights.

Project summary: This project will be based on a dataset of 4D flow MRI images of patients providing 3D blood velocity fields and LA wall motion. The approach will be divided into the following steps:

• Postprocessing of the 4D flow MRI images for the cohort
• Adaptation and application of highfidelity CFD simulations of intra-atrial hemodynamics
• Evaluation of the uncertainties of the 4D flow imaging approach: downsampling of the CFD simulations and comparison to in vivo 4D flow MRI data
• Evaluation of the predicting potential of the derived metrics: contrasting the in silico derived metrics with the clinical outcomes (occurrence of thromboembolic events).

Combining insights from biomechanics and cardiovascular fluid dynamics with clinical data, this project aims to substantially enhance our understanding of Left Atrium biomechanics, while setting the foundation for a clinically translational approach to predict thrombosis risk in patients.

Administrative aspects: This PhD position will be for 3 years, starting in the fall of 2026.

https://www.mines-stetienne.fr/en/research/centres-and-departments/center-biomedical-healthcare-engineering/

Student profile: Background in fluid mechanics and/or biomechanics. Curiosity for biomedical applications.