Finite-Difference Time-Domain Simulation for Three-dimensional Polarized Light Imaging

TL;DR

This paper introduces a 3D Maxwell solver based on Finite-Difference Time-Domain methods to simulate polarized light interaction with brain tissue, improving understanding and accuracy of nerve fiber reconstruction in 3D-PLI.

Contribution

It presents a novel 3D Maxwell solver for simulating polarized light in brain tissue, complementing existing Jones matrix models, to enhance fiber orientation accuracy.

Findings

Maxwell solver provides detailed electromagnetic wave propagation insights.

Simulation improves understanding of polarized light interaction with brain tissue.

Enhanced accuracy in fiber orientation reconstruction in 3D-PLI.

Abstract

Three-dimensional Polarized Light Imaging (3D-PLI) is a promising technique to reconstruct the nerve fiber architecture of human post-mortem brains from birefringence measurements of histological brain sections with micrometer resolution. To better understand how the reconstructed fiber orientations are related to the underlying fiber structure, numerical simulations are employed. Here, we present two complementary simulation approaches that reproduce the entire 3D-PLI analysis: First, we give a short review on a simulation approach that uses the Jones matrix calculus to model the birefringent myelin sheaths. Afterwards, we introduce a more sophisticated simulation tool: a 3D Maxwell solver based on a Finite-Difference Time-Domain algorithm that simulates the propagation of the electromagnetic light wave through the brain tissue. We demonstrate that the Maxwell solver is a valuable tool to better understand the interaction of polarized light with brain tissue and to enhance the accuracy of the fiber orientations extracted by 3D-PLI.