A viscoacoustic wave equation solver using modified Born series.

Advancements in medical ultrasound require fast and precise simulators for acoustic wave propagation. To address this, a frequency-domain numerical solver, the viscoacoustic Born series (VBS), is proposed for efficiently solving the two-dimensional/three-dimensional viscoacoustic wave equation. As an extension of the convergent Born series, the VBS retains the advantages of rapid computation and accurate convergence, with easily determined conditions, while incorporating sound speed, density, and attenuation. Theoretical formulations for preconditioning are developed to ensure convergence, and a multiscale strategy is introduced to enhance robustness and efficiency for calculation. Numerical tests on a range of fundamental and human tissue-mimicking models demonstrate that the VBS performs effectively and efficiently, even in high-impedance scenarios like transcranial ultrasound. The development of the VBS holds promise for advancing rapid focusing ultrasound and inversion-based imaging techniques.