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Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy
Published on: August 22, 2018
Diffusing-wave spectroscopy from head-like tissue phantoms: influence of a non-scattering layer.
Franck Jaillon1, Sergey E Skipetrov, Jun Li
1Universität Konstanz, Fachbereich Physik, 78457 Konstanz, Germany.
Optics Express
|June 17, 2009
Summary
A non-scattering layer, like the cerebrospinal fluid layer in the human head, significantly impacts light scattering measurements. Neglecting this layer can lead to underestimating the cortical diffusion coefficient by approximately 40%.
Area of Science:
- Biomedical Optics
- Medical Physics
- Turbid Media Optics
Background:
- Accurate measurement of light transport in turbid media is crucial for biomedical applications.
- The human head presents a complex multilayered structure with varying optical properties.
- Non-scattering layers, such as cerebrospinal fluid, can significantly alter light propagation and autocorrelation functions.
Purpose of the Study:
- To investigate the influence of a non-scattering layer on the temporal field autocorrelation function of multiply scattered light.
- To assess the impact of neglecting the non-scattering layer on the estimation of optical properties like the diffusion coefficient.
- To validate theoretical models and simulations against experimental phantom data.
Main Methods:
- Monte Carlo simulations were employed to model light transport in multilayered turbid media.
- The correlation-diffusion equation with specialized boundary conditions was used to predict autocorrelation functions.
- Experiments were conducted on multilayered phantoms incorporating a non-scattering layer.
- Field autocorrelation functions were measured at the surface of the phantoms.
Main Results:
- Monte Carlo simulations showed excellent agreement with the correlation-diffusion equation, accounting for non-diffusive transport in the non-scattering layer.
- Experimental measurements on phantoms aligned well with theoretical predictions and simulations for sufficient source-receiver distances.
- Neglecting the non-scattering cerebrospinal fluid layer resulted in an underestimation of the cortical diffusion coefficient by approximately 40% in human head models.
Conclusions:
- The presence of a non-scattering layer significantly affects the temporal field autocorrelation function of scattered light.
- Accurate modeling of light transport requires incorporating the effects of non-scattering layers, especially for deep tissue measurements.
- Underestimation of optical properties can occur if the non-scattering cerebrospinal fluid layer is ignored in analyses relevant to the human head.
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