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Journal of Biomedical Optics • Open Access

Experimental measurement of time-dependant photon scatter for diffuse optical tomography
Author(s): Niksa Valim; James L. Brock; Mark J. Niedre

Paper Abstract

Time-resolved measurement of early arriving photons through diffusive media has been shown to effectively reduce the high degree of light scatter in biological tissue. However, the experimentally achievable reduction in photon scatter and the impact of time-gated detection on instrument noise performance is not well understood. We measure time-dependent photon density sensitivity functions (PDSFs) between a pulsed laser source and a photomultiplier tube operating in time-correlated single-photon-counting mode. Our data show that with our system, measurement of early arriving photons reduces the full width half maximum of PDSFs on average by about 40 to 60% versus quasicontinuous wave photons over a range of experimental conditions similar to those encountered in small animal tomography, corresponding to a 64 to 84% reduction in PDSF volume. Factoring in noise considerations, the optimal operating point of our instrument is determined to be about the 10% point on the rising edge of the transmitted intensity curve. Time-dependant Monte Carlo simulations and the time-resolved diffusion approximation are used to model photon propagation and are evaluated for agreement with experimental data.

Paper Details

Date Published: 1 November 2010
PDF: 8 pages
J. Biomed. Opt. 15(6) 065006 doi: 10.1117/1.3523371
Published in: Journal of Biomedical Optics Volume 15, Issue 6
Show Author Affiliations
Niksa Valim, Northeastern Univ. (United States)
James L. Brock, Northeastern Univ. (United States)
Mark J. Niedre, Northeastern Univ. (United States)

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