21 July 1993 Extreme properties of backscattered light beam from biological tissue with inhomogeneity
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Proceedings Volume 1884, Static and Dynamic Light Scattering in Medicine and Biology; (1993); doi: 10.1117/12.148353
Event: OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, 1993, Los Angeles, CA, United States
Abstract
When a narrow collimated light beam is incident on biological tissue with inhomogeneity, the characteristics of light backscattered from the sample carry information about the inhomogeneity location. A model is developed, based on the diffusion approximation to radiative transfer, which yields analytical expression for backscattered light beam intensity from tissue with an inhomogeneity. The inhomogeneity may be an object with given reflection coefficient or a variation of scattering and absorption parameters of tissue. The relative contribution (delta) I/I of spatially limited inhomogeneity to backscattered light intensity is expressed in terms of inhomogeneity diffuse scattering amplitude and the probability density distribution of photon paths in depth. This contribution is a function of the positional inhomogeneity coordinates and the separation between the incident and receiving points on medium surface. It is shown that the function (delta) I/I has three conditional maximums and one minimum. The effect of medium scattering and absorption coefficients on conditional extremums of function (delta) I/I is studied. The discovered extremums of analytical solution to searchlight problem on backscattering of narrow pencil light from turbid medium with inhomogeneity permit us to formulate a simple theoretical method for solution of the location problem of the inhomogeneity in tissue. The model predictions make it possible to give correct quantitative interpretation of the experiment results on the change of the backscattered light beam intensity from tissue phantom due to the existence of small absorber.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yurii N. Barabanenkov, Andrei Yu. Kargashin, "Extreme properties of backscattered light beam from biological tissue with inhomogeneity", Proc. SPIE 1884, Static and Dynamic Light Scattering in Medicine and Biology, (21 July 1993); doi: 10.1117/12.148353; https://doi.org/10.1117/12.148353
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