Monte Carlo algorithm for efficient simulation of time-resolved fluorescence in layered turbid media

Area of Science:

• Biomedical Optics
• Computational Physics
• Medical Imaging

Background:

• Accurate simulation of light transport in turbid biological tissues is crucial for optical imaging and diagnostics.
• Time-resolved fluorescence measurements provide valuable information about tissue properties and function.
• Previous models often face limitations in handling complex layered structures and computational efficiency.

Purpose of the Study:

• To develop and validate an efficient Monte Carlo algorithm for simulating time-resolved fluorescence in layered turbid media.
• To calculate photon arrival time distributions and 3-D spatial generation probabilities.
• To apply the algorithm to a realistic two-layered head model for potential clinical applications.

Main Methods:

• An efficient Monte Carlo algorithm was implemented for simulating excitation and fluorescence photon bundle propagation.
• The algorithm assumes equal reduced scattering coefficients at excitation and emission wavelengths.
• Validation was performed by comparing results with the analytical solution of the diffusion equation for homogeneous media.

Main Results:

• The algorithm efficiently simulates time-resolved fluorescence in layered turbid media.
• It accurately calculates both time-of-flight distributions and 3-D spatial generation probabilities.
• Successful application to a two-layered model of the human head demonstrates its potential for in vivo studies.

Conclusions:

• The proposed Monte Carlo algorithm offers an efficient and accurate method for simulating time-resolved fluorescence in complex biological tissues.
• This tool can advance the understanding of light-tissue interactions and improve optical diagnostic techniques.
• The validated algorithm provides a robust framework for modeling fluorescence in layered structures like the human head.