Towards quantitative tissue absorption imaging by combining photoacoustics and acousto-optics

TL;DR

This paper introduces a purely experimental method for quantitative tissue absorption imaging by combining photoacoustics and acousto-optics, supported by a new theory and Monte Carlo validation.

Contribution

It presents a novel strategy for quantitative photoacoustic mapping using acousto-optic modulation and a theoretical framework validated through simulations.

Findings

The theory relates local absorption to measurable quantities.

Monte Carlo simulations confirm the theory's validity.

The method enables noninvasive tissue absorption quantification.

Abstract

We propose a strategy for quantitative photoacoustic mapping of chromophore concentrations that can be performed purely experimentally. We exploit the possibility of acousto-optic modulation using focused ultrasound, and the principle that photons follow trajectories through a turbid medium in two directions with equal probability. A theory is presented that expresses the local absorption coefficient inside a medium in terms of noninvasively measured quantities and experimental parameters. Proof of the validity of the theory is given with Monte Carlo simulations.