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Matthew Bruce

Principal Scientist/Engineer

Email

mbruce@apl.washington.edu

Phone

206-685-2283

Education

B.S. Electrical and Computer Engineering, Michigan Technological University, 1991

M.S. Electrical and Computer Engineering, Virginia Polytechnic University, 1993

Ph.D. Bioengineering, University of Washington, 2004

Matthew Bruce's Website

http://staff.washington.edu/mbruce

Publications

2000-present and while at APL-UW

High-frequency nonlinear Doppler contrast-enhanced ultrasound imaging of blood flow

Bruce, M., A. Hannah, R. Hammond, Z.Z. Khaing, C. Tremblay-Darveau, P.N. Burns, and C.P. Hofstetter, "High-frequency nonlinear Doppler contrast-enhanced ultrasound imaging of blood flow," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 67, 1778-1784, doi:10.1109/TUFFC.2020.2986486, 2020.

More Info

1 Sep 2020

Current methods for in vivo microvascular imaging (<1 mm) are limited by the tradeoffs between the depth of penetration, resolution, and acquisition time. Ultrasound Doppler approaches combined at elevated frequencies (<7.5 MHz) are able to visualize smaller vasculature and, however, are still limited in the segmentation of lower velocity blood flow from moving tissue. Contrast-enhanced ultrasound (CEUS) has been successful in visualizing changes in microvascular flow at conventional diagnostic ultrasound imaging frequencies (<7.5 MHz). However, conventional CEUS approaches at elevated frequencies have met with limited success, due, in part, to the diminishing microbubble response with frequency. We apply a plane-wave acquisition combined with the non-linear Doppler processing of ultrasound contrast agents at 15 MHz to improve the resolution of microvascular blood flow while compensating for reduced microbubble response. This plane-wave Doppler approach of imaging ultrasound contrast agents also enables simultaneous detection and separation of blood flow in the microcirculation and higher velocity flow in the larger vasculature. We apply singular value decomposition filtering on the nonlinear Doppler signal to orthogonally separate the more stationary lower velocity flow in the microcirculation and higher velocity flow in the larger vasculature. This orthogonal separation was also utilized to improve time-intensity curve analysis of the microcirculation, by removing higher velocity flow corrupting bolus kinetics. We demonstrate the utility of this imaging approach in a rat spinal cord injury model, requiring submillimeter resolution.

Blind source separation for clutter and noise suppression in ultrasound imaging: Review for different applications

Wildeboer, R.R., and 11 others including M. Bruce, "Blind source separation for clutter and noise suppression in ultrasound imaging: Review for different applications," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 67, 1497-1512, doi:10.1109/TUFFC.2020.2975483, 2020.

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1 Aug 2020

Blind source separation (BSS) refers to a number of signal processing techniques that decompose a signal into several "source" signals. In recent years, BSS is increasingly employed for the suppression of clutter and noise in ultrasonic imaging. In particular, its ability to separate sources based on measures of independence rather than their temporal or spatial frequency content makes BSS a powerful filtering tool for data in which the desired and undesired signals overlap in the spectral domain. The purpose of this work was to review the existing BSS methods and their potential in ultrasound imaging. Furthermore, we tested and compared the effectiveness of these techniques in the field of contrast-ultrasound super-resolution, contrast quantification, and speckle tracking. For all applications, this was done in silico , in vitro , and in vivo . We found that the critical step in BSS filtering is the identification of components containing the desired signal and highlighted the value of a priori domain knowledge to define effective criteria for signal component selection.

Imaging methods for ultrasound contrast agents

Averkiou, M.A., M.F. Bruce, J.E. Powers, P.S. Sheeran, and P.N. Burns, "Imaging methods for ultrasound contrast agents," Ultrasound Med. Biol., 46, 498-517, doi:10.1016/j.ultrasmedbio.2019.11.004, 2020.

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1 Mar 2020

Microbubble contrast agents were introduced more than 25 years ago with the objective of enhancing blood echoes and enabling diagnostic ultrasound to image the microcirculation. Cardiology and oncology waited anxiously for the fulfillment of that objective with one clinical application each: myocardial perfusion, tumor perfusion and angiogenesis imaging. What was necessary though at first was the scientific understanding of microbubble behavior in vivo and the development of imaging technology to deliver the original objective. And indeed, for more than 25 years bubble science and imaging technology have evolved methodically to deliver contrast-enhanced ultrasound. Realization of the basic bubbles properties, non-linear response and ultrasound-induced destruction, has led to a plethora of methods; algorithms and techniques for contrast-enhanced ultrasound (CEUS) and imaging modes such as harmonic imaging, harmonic power Doppler, pulse inversion, amplitude modulation, maximum intensity projection and many others were invented, developed and validated. Today, CEUS is used everywhere in the world with clinical indications both in cardiology and in radiology, and it continues to mature and evolve and has become a basic clinical tool that transforms diagnostic ultrasound into a functional imaging modality. In this review article, we present and explain in detail bubble imaging methods and associated artifacts, perfusion quantification approaches, and implementation considerations and regulatory aspects.

More Publications

Inventions

Improved Detection of Kidney Stones with Ultrasound

Record of Invention Number: 47629

Matthew Bruce

Disclosure

19 Feb 2016

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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