Photoacoustic Tomography in a Rectangular Reflecting Cavity

TL;DR

This paper introduces a fast iterative reconstruction algorithm for photoacoustic tomography within a rectangular reverberant cavity, addressing challenges posed by multiple acoustic reflections that hinder traditional free-space methods.

Contribution

It presents a novel iterative reconstruction method tailored for reverberant cavities, with proven convergence and demonstrated effectiveness through numerical simulations.

Findings

The algorithm converges under specific conditions.

It effectively reconstructs images in reverberant environments.

Numerical simulations confirm its efficiency and accuracy.

Abstract

Almost all known image reconstruction algorithms for photoacoustic and thermoacoustic tomography assume that the acoustic waves leave the region of interest after a finite time. This assumption is reasonable if the reflections from the detectors and surrounding surfaces can be neglected or filtered out (for example, by time-gating). However, when the object is surrounded by acoustically hard detector arrays, and/or by additional acoustic mirrors, the acoustic waves will undergo multiple reflections. (In the absence of absorption they would bounce around in such a reverberant cavity forever). This disallows the use of the existing free-space reconstruction techniques. This paper proposes a fast iterative reconstruction algorithm for measurements made at the walls of a rectangular reverberant cavity. We prove the convergence of the iterations under a certain sufficient condition, and demonstrate the effectiveness and efficiency of the algorithm in numerical simulations.