Enhanced k-Wave Simulations for Focused Ultrasound Therapy: A Pruned FFT Approach

Pruned Fast Fourier Transform ,Ultrasound Simulation, Wave propagation simulation , k-Wave , Pseudo-spectral methods

Wave propagation simulations are crucial for planning non-invasive medical treatments such as focused ultrasound therapy. However, these procedures often require multiple high-resolution simulations, leading to significant resource consumption and potential delays in critical treatments. This work presents a method to accelerate simulations performed using the k-Wave toolbox while maintaining an acceptable level of accuracy for pre-planning purposes. The k-Wave toolbox uses the k-space pseudo-spectral method with Fourier basis functions, where substantial computational time is spent on Fourier transforms. By substituting standard Fast Fourier Transform (FFT) computations with a pruned version of the algorithm, speedups of up to 1.7x for large simulation domains were achieved. The proposed approach, using the Acoustic Field Propagator with a bisection pruning algorithm, eliminates over 60% of spectral coefficients. Despite this reduction, focal point errors for a single transducer setup remain below 1%. Tests involving transcranial ultrasound and tumor ablation have shown consistent accuracy with only minor shifts in focus position. This improvement has the potential to significantly accelerate clinical workflows for treatment planning. While these principles primarily enhance the k-Wave toolbox, they could also benefit wave propagation simulations in other fields, particularly for weakly heterogeneous media.