Introduction and Numerical Validation of an Open-Source MATLAB Package for Quantitative Ultrasound Tomography via Ray-Born Inversion

Abstract

We present a MATLAB package for reconstructing sound-speed images from transmission ultrasound data. The package is based on two-point ray tracing and implements two complementary inversion strategies for image reconstruction. The first is a time-of-flight (ToF) method that produces low-resolution, low-contrast images with minimal artefacts. The second is a ray-Born inversion method, which integrates high-frequency ray theory with the Born approximation to generate high-resolution sound-speed reconstructions. Early iterations of the ToF reconstruction are used to provide an initial estimate for the more advanced ray-Born approach. The core of this software package consists of four ray-tracing algorithms, whose accuracy is assessed in this study with respect to known analytical trajectories and accumulated acoustic path lengths. Furthermore, both image-reconstruction strategies have been validated numerically with simulated synthetic datasets and experimentally with open-source in-vitro and in-vivo datasets in related parallel studies.