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Published 1995 | public
Book Section - Chapter

Monte Carlo Modeling of Light Transport in Tissues


Monte Carlo simulations of photon propagation offer a flexible yet rigorous approach toward photon transport in turbid tissues. This method simulates the "random walk" of photons in a medium that contains absorption and scattering. The method is based on a set of rules that govern the movement of a photon in tissue. The two key decisions are (1) the mean free path for a scattering or absorption event, and (2) the scattering angle. Figure 4.1 illustrates a scattering event. At boundaries, a photon is reflected or moves across the boundary. The rules of photon propagation are expressed as probability distributions for the incremental steps of photon movement between sites of photon—tissue interaction, for the angles of deflection in a photon's trajectory when a scattering event occurs, and for the probability of transmittance or reflectance at boundaries. Monte Carlo light propagation is rigorous yet very descriptive. However, this method is basically statistical in nature and requires a computer to calculate the propagation of a large number of photons. To illustrate how photons propagate inside tissues, a few photon paths are shown in Fig. 4.2.

Additional Information

© 1995 Springer Science+Business Media. We wish to acknowledge the contributions of Scott A. Prahl, Marleen Keijzer, Iyad Saidi, and A. J. Welch, who have been our collaborators during the development of these Monte Carlo simulations. This work was supported by the NIH (R29-HL45045) and the Department of the Navy (N00015-91-J-1354).

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August 20, 2023
January 13, 2024