RÉSUMÉ
We propose a new numerical model to describe thrombus formation in cerebral aneurysms. This model combines CFD simulations with a set of bio-mechanical processes identified as being the most important to describe the phenomena at a large space and time scales. The hypotheses of the model are based on in vitro experiments and clinical observations. We document that we can reproduce very well the shape and volume of patient specific thrombus segmented in giant aneurysms.
Sujet(s)
Anévrysme intracrânien/complications , Anévrysme intracrânien/anatomopathologie , Modèles biologiques , Analyse spatio-temporelle , Thrombose/complications , Thrombose/anatomopathologie , Simulation numérique , Hémorhéologie , Cellules endothéliales de la veine ombilicale humaine/métabolisme , Humains , Anévrysme intracrânien/physiopathologie , ARN messager/génétique , ARN messager/métabolisme , Contrainte mécanique , Thrombose/physiopathologieRÉSUMÉ
Intracranial aneurysms are a common pathologic condition with a potential severe complication: rupture. Effective treatment options exist, neurosurgical clipping and endovascular techniques, but guidelines for treatment are unclear and focus mainly on patient age, aneurysm size, and localization. New criteria to define the risk of rupture are needed to refine these guidelines. One potential candidate is aneurysm wall motion, known to be associated with rupture but difficult to detect and quantify. We review what is known about the association between aneurysm wall motion and rupture, which structural changes may explain wall motion patterns, and available imaging techniques able to analyze wall motion.
Sujet(s)
Rupture d'anévrysme/diagnostic , Rupture d'anévrysme/physiopathologie , Imagerie diagnostique , Hémodynamique/physiologie , Anévrysme intracrânien/diagnostic , Anévrysme intracrânien/physiopathologie , Muscles lisses vasculaires/physiopathologie , Animaux , Humains , Mâle , Fantômes en imagerie , Appréciation des risques , Sensibilité et spécificitéRÉSUMÉ
The aim of this work is to introduce a novel 3-D model of pulsating vessels, through which the dynamic acoustic response of arterial regions can be predicted. Blood flow is numerically simulated by considering the fluid-dynamic displacements of the scatterers (erythrocytes), while a mechanical model calculates the wall displacement due to fluid pressure. The acoustic characteristics of each region are simulated through the FIELD software. Two numerical phantoms of a carotid artery surrounded by elastic tissue have been developed to illustrate the model. One of them includes a plaque involving a 50% stenosis. B-mode and M-mode images are produced and segmented to obtain the wall displacement profile. A cylindrical holed phantom made of cryogel mimicking material has been constructed for the model validation. In pulsatile flow conditions, fluid and wall displacements have been measured by Doppler ultrasound methods and quantitatively compared to simulated M-mode images, showing a fairly good agreement.
