Abstract
In contrast-enhanced echography, the simulation of nonlinear propagation of ultrasound through a population of oscillating microbubbles imposes a computational challenge. Also, the numerical complexity increases because each scatterer has individual properties. To address these problems, the Iterative Nonlinear Contrast Source (INCS) method has been extended to include a large population of nonlinearly responding microbubbles. The original INCS method solves the Westervelt equation in a four-dimensional spatiotemporal domain by generating increasingly accurate field corrections to iteratively update the acoustic pressure. The field corrections are computed by the convolution of a nonlinear contrast source with the Green's function of the linear background medium. Because the convolution integral allows a coarse discretization, INCS can efficiently deal with large-scale problems. To include a population of microbubbles, these are considered as individual contrast point sources with their own nonlinear response. The field corrections are computed as before, but now, in each iteration, the temporal signature of each contrast point source is computed by solving the bubble's Marmottant equation. Physically, each iteration adds an order of multiple scattering. Here, the performance of the extended INCS method and the significance of multiple scattering is demonstrated through various results from different configurations.
Original language | English |
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Pages (from-to) | 2209-2222 |
Number of pages | 14 |
Journal | Journal of the Acoustical Society of America |
Volume | 153 |
Issue number | 4 |
DOIs | |
Publication status | Published - 11 Apr 2023 |
Bibliographical note
Funding Information:This publication is part of the project “Optoacoustic sensor and ultrasonic microbubbles for dosimetry in proton therapy” of the Dutch National Research Agenda which is partly financed by the Dutch Research Council. The authors would like to thank Gonzalo Collado Lara, Nathan Blanken, Paul van Neer, and Nico de Jong for their fruitful discussions about this topic.
Publisher Copyright:
© 2023 Author(s).