Access Type

Open Access Dissertation

Date of Award

January 2015

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Physics and Astronomy

First Advisor

Zhi-Feng Huang

Second Advisor

Neb Duric

Abstract

Ultrasound tomography is an emerging modality for imaging breast tissue for the detection of disease. Using the principles of full waveform inversion, high-resolution quantitative sound speed and attenuation maps of the breast can be created. In this thesis, we introduce some basic principles of imaging breast disease and the formalism of sound wave propagation. We present numerical methods to model acoustic wave propagation as well methods to solve the corresponding inverse problem. Numerical simulations of sound speed and attenuation reconstructions are used to assess the efficacy of the algorithm. A careful review of the preprocessing techniques needed for the successful inversion of acoustic data is presented. Ex vivo and in vivo sound speed reconstructions highlight the significant improvements that are made upon commonly used travel time sound speed reconstruction methods. Note that we do not present ex vivo or in vivo attenuation reconstructions in this thesis. For the sound speed images, the higher resolution and contrast of the waveform method will hopefully allow a radiologist to make a more informed diagnosis of breast disease. A comparison of full waveform sound speed imaging to MRI shows a great deal of concordant findings. Lastly, we give examples of the use of full waveform inversion sound speed imaging in a clinical setting.

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