Reconstruction of ultrasound tomography for cancer detection using total least squares and conjugate gradient method

Ray-based inversion accounting for scattering for biomedical ultrasound tomography

“…the receivers adjacent to r = N r are r = {N r − 1, 1}.) Using ( 73), the two auxiliary rays used in (72) are replaced by two adjacent linked rays, which have already been calculated. (Note that ( 72) is used in this study.)…”

“…For the latter, the amplitude on the second point along the ray was calculated using the analytical formula (20), and using an assumption that a neighborhood of each emission point with a radius larger than the ray spacing is acoustically homogeneous. The Jacobian on the rays' points was computed using (72), which required two auxiliary rays for each linked ray (emitter-receiver pair).…”

Therapeutic Systems and Technologies: State-of-the-Art Applications, Opportunities, and Challenges

“…During ultrasound tomography, an array of transducers is used to collect information about the scattered field resulting from the excitation of an individual transducer to a region of interest. The process of exciting a unique transducer element while the rest of the array collects measurements is repeated until a predetermined number of elements have been excited [130]- [132]. To implement this in hardware, the collected data, usually on the order of several GBs, is transferred to a PC and then processed with custom reconstruction algorithms [133].…”

“…Another method of determining these properties is the Distorted Born Iterative (DBI) method [130], [131], [136] which involves interactively solving the well-posed forward scattering problem followed by solving of the ill-posed inverse scattering problem to gain information about the total field within the ROI and the scattering function, respectively [131], [132]. This method relies upon the Born approximation, which becomes increasingly inaccurate when using high frequencies or imaging strongly scattering medium.…”

“…It was found that TTLS algorithm provides better results for the reconstructed images. In addition, [131], [132] explored different approaches of the regularized TLS and the conjugate gradient method, respectively.…”