A New Paradigm in Ultrasonic Image Formation: Inverse Scattering

Addressing the Problem

Ultrasound imaging has several advantages over competing imaging technologies in that is does not use ionizing radiation and is considered one of the safest imaging modalities. For several decades, ultrasonic image formation has relied upon simple delay and sum beam formation. While such techniques have been highly developed and can provide real-time imaging capabilities, the resulting images are characterized by speckle and are affected by reverberation and aberration. To improve upon existing ultrasonic imaging techniques, a fundamental change in the paradigm of image formation must be adopted. This work will greatly alter the quality of next generation ultrasonic images by fundamentally changing ultrasonic image formation approaches.

In this project, a novel paradigm for image formation in ultrasound will be explored and demonstrated. This novel paradigm will utilize inverse scattering techniques, high-bandwidth ultrasound array technologies, and advances in large-scale computing technologies (e.g., greater performance and lower cost) to create images of tissues. As a result, image formation based on inverse scattering will produce speckle-free images and images that are unaffected by aberration and reverberation artifacts. These images will be quantitative and provide maps of sound speed and attenuation of tissues. Inverse scattering techniques have not been applied to image formation in clinical ultrasound because of the complex nature of inverse scattering algorithms and the inability to rapidly reconstruct image objects in a timely fashion. However, recent advances in inverse scattering techniques from researchers at Illinois, and expertise in computer technologies, have resulted in fast reconstruction techniques. These advances suggest that the time is ripe for implementing inverse scattering as a new imaging paradigm for clinical ultrasound.

Research Goals

The overall goal of the proposed research is to develop nonlinear inverse scattering approaches for ultrasonic image formation that will provide significant improvements over current ultrasonic imaging approaches. The researchers’ hypothesis is that, given sufficient data and bandwidth from ultrasonic signals based on scattering from tissues, inverse scattering approaches can be implemented to provide images without reverberation, aberration and speckle artifacts.

Current Activities

  • Develop inverse scattering algorithms tailored to a clinical ultrasound imaging arrays;
  • Implement the full wave inverse scattering algorithms computationally using parallel computing resources; and
  • Demonstrate the image formation capabilities using well-characterized tissue mimicking samples.