Projet ANR 18-CE45-0014-01

Human and Animal NUmerical Models for the crANio-spinal system

Modèles numériques humain et animal du système cranio-spinal
    Plenary meeting
    14 - 15 janvier 2020 Toulouse. Program.
    Kick-Off meeting
    28 - 29 janvier 2019 Reims. Program.
    Coordinators and Partners

  • Project coordinator and partner 1 : Stéphanie Salmon, Laboratoire de Mathématiques (CNRS FRE 2011), Université de Reims Champagne-Ardenne
  • Partner 2 : Patricia Cathalifaud, Insitut de Mécanique des Fluides de Toulouse.
  • Partner 3 : Muriel Mescam, Centre de Recherche Cerveau et Cognition (CNRS UMR5549).
  • Partner 4 : Olivier Balédent, Chimere, Université de Picardie Jules Verne.

  • Task 1 : WP1 Images acquisition (coordinator: Olivier Balédent).
  • Task 2 : WP2 Information extraction and modeling (coordinator: Nicolas Passat).
  • Task 3 : WP3 Numerical models (coordinator: Mokhtar Zagzoule).
  • Task 4 : WP4 Confrontation : numerical simulations / experimental data on animal and human (coordinator: Muriel Mescam).
    Project summary
    The relevance of numerical simulations in the field of medicine is now obvious. They give access to information that could not be obtained in vivo or non-invasively in humans. Animal models also constitute a means of obtaining such information. Nevertheless, their use remains limited by ethical issues, but also by uncertainties related to the compliance between humans and animals. In this context, there exist very few numerical approaches devoted to the animal. However, such approaches would allow for tackling ethical questions by minimizing experiments on animals. Indeed, coupling in vivo technics on animals -respectful of ethics- with in silico approaches would open the way to handling complex physiological parameters and studying compatibilities between human and animal models. Then, we propose to design numerical models dedicated both to animal and human. In particular, we will develop numerical models of the craniospinal system (liquid flows: blood and cerebrospinal fluid - CSF) on human and marmoset monkey (Callithrix jacchus), a small primate frequently used in preclinical studies due to its phylogenetic proximity to the human. Indeed, the brain has not been extensively studied from the side of its fluid dynamics. However, recent studies show that blood flows and CSF hydrodynamics (in particular, intracranial pressure oscillations) have a crucial role in the correct functions and perfusion of the brain. These considerations motivate research work on interactions between blood and CSF. By contrast to static tissue studies, that can be carried out ex vivo, the blood flow and CSF mechanics have to be studied in situ, on living subjects. For ethical and technical reasons, magnetic resonance imaging (MRI) constitutes a relevant tool since it allows for the non-invasive acquisition of images. In addition, recent progress in MRI now enables to observe the flows in 3 dimensions + time, for quantifying in vivo oscillating CSF and flowing blood. Images will be acquired on humans and marmosets. The extraction of various kinds of information (geometry of vessels and CSF compartments; networks structure; velocimetric data) from both 3 and 7 Tesla MRI images - never used for such purpose - will require to develop specific methods and tools dedicated to marmoset images, that induce specific challenges (resolution, signal-to-noise ratio). For similar reasons, numerical models especially designed for blood and CSF simulation will be proposed, in order to study the fluid-fluid-structure coupling and to look for physical parameters of interest. Models of different dimensions will be considered: 1D models for global behaviour analysis in complete networks; 2D models for investigating intracranial pressure autoregulation process; 3D models for observing accurate behaviour of flows. The complexity of the involved physiological mechanisms makes the determination of important physical parameters a hard task. Numerical models then constitute an exploratory tool of high interest. Numerical animal models will be finally correlated to human models, with the purpose to assess the validity of the proposed hypotheses and the potential transferability from animal to human. This project, highly pluridisciplinary, gathers mathematicians, computer scientists, biologists and medical doctors. The models will be developed and released as open-source softwares, thus guaranteeing their wide diffusion within the scientific communities. They will contribute to improve our understanding of mechanisms related to cerebral pathologies.