Photoacoustic tomography as a method to estimate the optical fluence distribution in turbid media

Lawrence C M Yip; Elina Rascevska; Parsa Omidi; Jeffrey J L Carson

doi:10.1364/BOE.496078

Photoacoustic tomography as a method to estimate the optical fluence distribution in turbid media

Biomed Opt Express. 2023 Sep 5;14(10):5036-5046. doi: 10.1364/BOE.496078. eCollection 2023 Oct 1.

Authors

Lawrence C M Yip^{1

2}, Elina Rascevska^{1

3}, Parsa Omidi³, Jeffrey J L Carson^{1

2

3

4}

Affiliations

¹ Lawson Health Research Institute, Imaging Program, 268 Grosvenor St., London, Canada, N6A 4V2, Canada.
² Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, 1151 Richmond St, London, Canada, N6A 3K7, Canada.
³ Western University, School of Biomedical Engineering, 1151 Richmond St, London, Canada, N6A 3K7, Canada.
⁴ Western University, Schulich School of Medicine and Dentistry, Department of Surgery, 1151 Richmond St, London, Canada, N6A 3K7, Canada.

Abstract

Currently, there are no non-invasive experimental methods available for measuring optical fluence distributions in tissue. We present photoacoustic tomography (PAT) as a method to approximate the relative optical fluence distribution in a homogeneous optically scattering medium. Three-dimensional photoacoustic images were captured with a near-full view PAT scanner in phantoms with known optical absorption and scatter properties. Resultant 3D PAT images were compared to the expected optical fluence distributions from Monte Carlo simulations and diffusion theory using volumetric and shape analysis. Volumetric analysis of PAT images compared well with the optical fluence distributions from simulation. Dice similarity coefficients ranged from 51 to 82%. The reduced scattering coefficient estimated from PAT images compared well to estimates from simulations for values below 0.5 mm^-1. Near full-view PAT has been found to be useful for estimating the optical fluence distribution in an optically scattering medium. Further development is needed to extend the measurement range.