Project promoter: Sébastien Salles (Chercheur ATIP-Avenir)
Cardiovascular disease is a leading cause of mortality in the western world, and fibrosis is a common pathology in cardiovascular disease. In the myocardium, fibrosis leads to electrical and mechanical dysfunction, cardiac fiber disarray, and increasing tissue stiffness, affecting both diastolic and systolic functions. Moreover, myocardial fibrosis is associated with a worsened prognosis in many disorders. Therefore, early detection of the amount of fibrosis is essential, as it could have therapeutic implications. This research project addresses the issue of the non-invasive characterization of cardiac and vascular tissue using natural events occurring in the cardiovascular system. Currently, there is no technique permitting the sensitive evaluation of these properties available for clinical routine. This scientific project aims to develop and validate non-invasive and relatively inexpensive ways of assessing cardiac and vascular tissue properties (local wall stiffness, fiber orientation and fibrosis level), in vivo, in humans.
Thanks to ATIP-AVENIR grant, the team will focus on developing and validating new methods able to characterize the cardiac tissue stiffness and orientation using the propagation of natural mechanical waves occurring in the left ventricle of the heart. With the advancement of 3D high frame-rate ultrasound scanners, the study of the natural mechanical wave propagation for detecting cardiovascular diseases has become a major research field across the world. However, only the speed of the different mechanical waves occurring naturally in the myocardium have been studied. We propose to develop a novel ultrasound imaging method able to quantify both tissue elasticity and tissue fibers orientation using 3D high frame-rate ultrasound imaging and the propagation of mechanical waves naturally produced by the heart. First, the proposed technique will be evaluated by simulation and experimentally. Several tissue-mimicking phantoms with local stiffness and orientation variations will be made and used for experimental validation. The feasibility of 3D mechanical wave trajectory reconstruction will then be evaluated in preliminary clinical studies. This novel technique will provide new in vivo knowledge of tissue-related cardiac physio-pathological processes. Development with ultrasound technology will furthermore provide an accessible, cost-effective, and real-time method that will be well adapted to screening and therapeutic follow-up in patients.
Human, In-vivo, preliminary result. This figure shows the firsts in-vivo 3D trajectory reconstruction of specific mechanical waves produced by the heart and traveling in the left-ventricle myocardium. The streamlines indicate the path of the mechanical wave; on the top, the colormap indicates the path’s orientation, while on the bottom, the colormap indicated the mechanical wave speed. Note that the raw ultrasound data came from a clinical scanner https://patents.google.com/patent/US20210085294A1/en
International collaborations:
Solveig Fadness, Lasse Lovstakken (NTNU, ISB, Norway)
National collaborations:
Francois Varray, Hervé Liebgott (CREATIS, Lyon)
Membres de l’équipe:
Patent:
S. Salles, L. Lovstakken, H. Torp, “Ultrasound Cardiac Processing”, 2021, General Electric (Dehns ref. 7.144988, US application number 16/585.034)