A simulation framework for pulse wave and vector flow imaging using fluid–structure interaction and FIELD-II simulations

Abstract

Pulse Wave Imaging (PWI) utilizes ultrasound elasticity imaging and normalized cross-correlation (NCC) tracking pulse-induced arterial wall distension propagations to perform localized pulse wave velocity and assess arterial compliance mapping for the early detection of vulnerable carotid plaques. At the same time, Vector Flow Imaging (VFI) using a singular value decomposition filter and NCC with axially and laterally shifted axial kernels provides blood flow information. In this study, fluid–structure interaction (FSI) simulations (FEBio) were integrated with FIELD-II ultrasound imaging simulations to optimize both PWI and VFI for simultaneous estimation of compliance and flow in structures of variable vessel geometry and plaque stiffness at distinct ultrasound parameters. The spatiotemporal maps of wall distension rate between FSI ground truth and PWI method were in excellent agreement (r2 = 0.968–0.982) at plane wave angles compounding at (−1°, 0, 1°) and NCC window size of 7 wavelengths in both straight and 87% stenotic vessel geometries. Similar agreement was found in 2D blood flow velocity estimation between FSI ground truth and VFI with a maximum correlation of 0.9464 at the systolic upstroke and r2 of 0.7426 at the angles of (−2°, 0, 2°) and NCC window size of 60 wavelengths. Overall, the framework presented herein allowed PWI and VFI technique validation and optimization prior to in vivo application.