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Journal of Biomedical Optics • Open Access

Spectroscopic method for determination of the absorption coefficient in brain tissue

Paper Abstract

I use Monte Carlo simulations and phantom measurements to characterize a probe with adjacent optical fibres for diffuse reflectance spectroscopy during stereotactic surgery in the brain. Simulations and measurements have been fitted to a modified Beer-Lambert model for light transport in order to be able to quantify chromophore content based on clinically measured spectra in brain tissue. It was found that it is important to take the impact of the light absorption into account when calculating the apparent optical path length, lp, for the photons in order to get good estimates of the absorption coefficient, µa. The optical path length was found to be well fitted to the equation lp=a+b ln(Is)+c ln(µa)+d ln(Is)ln(µa), where Is is the reflected light intensity for scattering alone (i.e., zero absorption). Although coefficients a-d calculated in this study are specific to the probe used here, the general form of the equation should be applicable to similar probes.

Paper Details

Date Published: 1 September 2010
PDF: 9 pages
J. Biomed. Opt. 15(5) 057005 doi: 10.1117/1.3495719
Published in: Journal of Biomedical Optics Volume 15, Issue 5
Show Author Affiliations
Johannes D. Johansson, Linköping Univ. (Sweden)

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