Building an open-source simulation platform of acoustic radiation force-based breast elastography

Abstract

Ultrasound-based elastography including strain elastography (SE), acoustic radiation force Impulse (ARFI) imaging, point shear wave elastography (pSWE) and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published virtual simulation platform built for ultrasound quasi-static breast elastography toward acoustic radiation force-based breast elastography. Consequently, the extended virtual breast elastography simulation platform can be used to validate image pixels with known underlying soft tissue properties (i.e. “ground truth”) in complex, heterogeneous media, enhancing confidence in elastographic image interpretations. The proposed virtual breast elastography system inherited four key components from the previously published virtual simulation platform: an ultrasound simulator (Field II), a mesh generator (Tetgen), a finite element solver (FEBio) and a visualization and data processing package (VTK). Using a simple message passing mechanism, functionalities have now been extended to acoustic radiation force-based elastography simulations. Examples involving three different numerical breast models with increasing complexity – one uniform model, one simple inclusion model and one virtual complex breast model derived from magnetic resonance imaging data, were used to demonstrate capabilities of this extended virtual platform. Overall, simulation results were compared with the published results. In the uniform model, the estimated shear wave speed (SWS) values were within 4% compared to the predetermined SWS values. In the simple inclusion and the complex breast models, SWS values of all hard inclusions in soft backgrounds were slightly underestimated, similar to what has been reported. The elastic contrast values and visual observation show that ARFI images have higher spatial resolution, while SSI images can provide higher inclusion-to-background contrast. In summary, our initial results were consistent with our expectations and what have been reported in the literature. The proposed (open-source) simulation platform can serve as a single gateway to perform many elastographic simulations in a transparent manner, thereby promoting collaborative developments.

An Application of Super-Resolution Generative Adversary Networks for Quasi-Static Ultrasound Strain Elastography: A Feasibility Study

“…high-frequency ultrasound data using novel beam-forming technology for training. Given the availability of an advanced ultrasound elastography simulation platform [38], [39], computer-simulated but realistic data of this kind can be used for training purposes. Now we have a better understanding the relationship between CNN-based super-resolution and noise removal [45], novel CNN models can be designed to improve the generator network accordingly.…”

“…The simulated inclusion was 5 times stiffer than its background. Computersimulated ultrasound data were created using the combination of finite element (FE; ANSYS Inc., PA, USA) and Field II ultrasound simulations [38], [39]. Field II simulations were done to mimic a 7.5 MHz linear array transducer.…”

A two-dimensional (2D) systems biology-based discrete liver tissue model: A simulation study with implications for ultrasound elastography of liver fibrosis

“…Acoustic radiation force-induced SWE [1] has more complex SW wavefronts and will induce (tissue) excitations with broader frequency components. Our group is in the process of extending the proposed discrete liver tissue model into an open-source elastography simulation platform [38][39] to enable more realistic ultrasound elastography simulations. In parallel, rigorous validations of the proposed discrete liver tissue model using a pre-clinical animal model will enable us to tune rules related to the systems biology simulations and conversions into mechanical properties.…”

Fourier-Domain Shift Matching: A Robust Time-of-Flight Approach for Shear Wave Speed Estimation

“…The numerical phantom ( i.e. Model 1 in [21]) had a uniform shear modulus of 1.59 kPa, corresponding to an expected shear wave speed of 1.26 m/s. A single simulated acoustic push excited the tissue at the center of the region-of-interest.…”

“…It is important to note that, in the original 2D-FT method [19], only phase SWS values were obtained and here we approximated the group SWS by averaging phase SWS values (see Section III-B3). In this feasibility study, these comparisons and evaluations were conducted using computer-simulated SWS data [21], a commercial elastography phantom (Model 049, CIRS, VA) and ex vivo tissues. To date, such an algorithmic comparison has not be published.…”