A Graph-Based Realistic 3D Microvascular Flow Simulation for Ultrasound

This work demonstrates a microvascular ultrasound flow simulator implementing a volume-preserving static flow approximation in a microvascular graph, suitable for use with ultrasound simulation. The hypothesis is that volume-preserving particle flow enables the simulation of the microvasculature together with tissue such that the effects of echo-cancellation as seen in vivo is replicated. To enable volume-preserving flow, volumetric flow mapping of bifurcations and a full connected arterial-venous vessel coupling through the capillaries is implemented. The simulator is used together with either computer-generated microvasculature or with microvasculatures extracted from an ex-vivo segmented 3D µCT dataset from the excised kidney of a Sprague-Dawley rat, with the simulation result of the latter being visually validated against a flow image (power-Doppler) of the same rat. Simulating the blood flow together with tissue results in a flow image closely resembling one derived from real in-vivo flow data. This thus confirms that by circulating continous flow in a graph vasculature, blood-flow images of the microvasculature necessitating echo cancellation can be replicated in a simulator.