Separation of absorption and scattering properties of turbid media using relative spectrally resolved cw radiance measurements

Serge Grabtchak,William M Whelan

doi:10.1364/boe.3.002371

Abstract

We present a new method for extracting the effective attenuation coefficient and the diffusion coefficient from relative spectrally resolved cw radiance measurements using the diffusion approximation. The method is validated on both simulated and experimental radiance data sets using Intralipid-1% as a test platform. The effective attenuation coefficient is determined from a simple algebraic expression constructed from a ratio of two radiance measurements at two different source–detector separations and the same 90° angle. The diffusion coefficient is determined from another ratio constructed from two radiance measurements at two angles (0° and 180°) and the same source–detector separation. The conditions of the validity of the method as well as possible practical applications are discussed.

Highlights

Extraction of optical parameters of biological tissues is of great interest for biomedical optics for tissue diagnostics, treatment planning or monitoring [1,2,3]
A detailed coverage of various aspects of light interaction with turbid media is given in several excellent books on this subject [8,9,10].The effective attenuation coefficient quantifies the combined effect due to absorption and scattering and is of great value by itself
Angle) and normalizing the radiance data to the value obtained at the shortest source–detector separation (6.5 mm, that is approximately 6 optical penetration depths away from the light source), we demonstrated a successful recovery of μeff(λ) but failed to recover D(λ)

Summary

Introduction

Extraction of optical parameters of biological tissues is of great interest for biomedical optics for tissue diagnostics, treatment planning or monitoring [1,2,3]. A detailed coverage of various aspects of light interaction with turbid media is given in several excellent books on this subject [8,9,10].The effective attenuation coefficient quantifies the combined effect due to absorption and scattering and is of great value by itself. Both μeff(λ) and D(λ) can be determined by fitting measured optical data to a diffusion model.

Objectives

Methods

Results

Conclusion