A method for ascertaining a fluid-dynamic characteristic value of a resilient vascular tree, through which a fluid flows in a pulsating manner, is provided. At least one 2D projection, respectively, of the resilient vascular tree is generated by a projection device from different angles of projection, and a digital 3D reconstruction of the vascular tree is generated by an analysis device based on of the 2D projections. A geometry of at least one vessel of the resilient vascular tree is estimated based on the 3D reconstruction, and at least one fluid state in the resilient vascular tree is ascertained from the geometry and predetermined resilient properties of the resilient vascular tree. The at least one fluid-dynamic characteristic value is calculated as a function of the at least one fluid state.
