| Abstract: |
| In this talk, we present a mathematical model and analysis for a new method to estimate the sound speed in ultrasound imaging.
We first perform a detailed analysis of the point-spread function of an imaging system in the presence of a mismatch between the true sound speed in the medium and the speed used in the reverse-time imaging function. This analysis leads to an estimator of the sound speed in the presence of a point-like reflector (a guide star).
In a second part, we consider a random multiscale medium (modeling biological tissue for instance) and use stochastic homogenization techniques to derive a representation formula for the scattered field. We then show that statistical moments of the imaging functional can be recovered from data corresponding to a single realization of the medium. We demonstrate that the point-spread function can be extracted directly from speckle patterns, making it possible to estimate the effective sound speed even in the absence of a point-like reflector. |
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