Tutorial on the Use of the Photon Diffusion Approximation for Fast Calculation of Tissue Optical Properties

J Biophotonics. 2024 Oct 26:e202400257. doi: 10.1002/jbio.202400257. Online ahead of print.

Abstract

Computer simulations, which are performed at a single wavelength at a time, have been traditionally used to estimate the optical properties of tissues. The results of these simulations need to be interpolated. For a broadband estimation of tissue optical properties, the use of computer simulations becomes time consuming and computer demanding. When spectral measurements are available for a tissue, the use of the photon diffusion approximation can be done to perform simple and direct calculations to obtain the broadband spectra of some optical properties. The additional estimation of the reduced scattering coefficient at a small number of discrete wavelengths allows to perform further calculations to obtain the spectra of other optical properties. This study used spectral measurements from the heart muscle to explain the calculation pipeline to obtain a complete set of the spectral optical properties and to show its versatility for use with other tissues for various biophotonics applications.

Keywords: heart muscle; inverse adding‐doubling simulations; photon diffusion approximation; spectral identification of tissue components; spectral optical properties.