Accelerating ultrasound speed of sound tomography through reflection and transmission imaging

Imaging of speed of sound holds great promise for medical detection and diagnosis since it is a quantitative, physical property of tissues not imaged by other means. The full Waveform Inversion (FWI) based method can build speed of sound images with high spatial resolution but it is computationally very demanding. The iterative Algebraic Reconstruction Technique (ART) is a favored choice for fast projection reconstruction problems, but its convergence, like that of other algorithms, is strongly limited when used for limited angle tomography, i.e. tomography without full 360° projection data. Limited angle ART is prone to yield inaccurate results and directionally dependent artifacts. Other speed of sound (SOS) imaging methods with fast reconstruction properties can only provide coarse resolution with high variance and bias. Here, we propose a fast SOS imaging method with good quantitative and spatial fidelity.