Diffuse ultrasound computed tomography for medical imaging

TL;DR

This paper introduces a diffuse ultrasound computed tomography method inspired by seismic interferometry, aiming to improve medical imaging by reducing acquisition time, calibration needs, and noise, with promising simulation results.

Contribution

The paper presents a novel diffuse ultrasound tomography approach that leverages ambient field interferometry principles, eliminating calibration and enhancing robustness against noise.

Findings

Accurate travel time measurements achieved with fewer emitters.

Spectral-element simulations validate the method's effectiveness.

Potential for improved tomographic reconstructions in breast imaging.

Abstract

An alternative approach to ultrasound computed tomography (USCT) for medical imaging is proposed, with the intent to (i) shorten acquisition time for devices with a large number of emitters, (ii) eliminate the calibration step, and (iii) suppress instrument noise. Inspired by seismic ambient field interferometry, the method rests on the active excitation of diffuse ultrasonic wavefields and the extraction of deterministic travel time information by inter-station correlation. To reduce stochastic errors and accelerate convergence, ensemble interferograms are obtained by phase-weighted stacking of observed and computed correlograms, generated with identical realizations of random sources. Mimicking a breast imaging setup, the accuracy of the travel time measurements as a function of the number of emitters and random realizations can be assessed both analytically and with spectral-element simulations for realistic breast phantoms. The results warrant tomographic reconstructions with straight- or bent-ray approaches, where the effect of inherent stochastic fluctuations can be made significantly smaller than the effect of subjective choices on regularisation. This work constitutes a first conceptual study and a necessary prelude to future implementations.