1. Radiative transfer equation modeling by streamline diffusion modified continuous Galerkin method
- Author
-
Xavier Intes, Feixiao Long, Fengyan Li, and Shiva P. Kotha
- Subjects
Research Papers: Imaging ,Monte Carlo method ,Biomedical Engineering ,010103 numerical & computational mathematics ,Models, Biological ,01 natural sciences ,Diffusion ,010309 optics ,Biomaterials ,Imaging, Three-Dimensional ,Optics ,Streamline diffusion ,Photon transport in biological tissue ,0103 physical sciences ,medicine ,Radiative transfer ,Humans ,Tomography, Optical ,Applied mathematics ,Computer Simulation ,0101 mathematics ,Optical tomography ,Physics ,medicine.diagnostic_test ,business.industry ,Monte Carlo method for photon transport ,Atomic and Molecular Physics, and Optics ,Finite element method ,Electronic, Optical and Magnetic Materials ,business ,Monte Carlo Method ,Algorithms ,Gaussian beam - Abstract
Optical tomography has a wide range of biomedical applications. Accurate prediction of photon transport in media is critical, as it directly affects the accuracy of the reconstructions. The radiative transfer equation (RTE) is the most accurate deterministic forward model, yet it has not been widely employed in practice due to the challenges in robust and efficient numerical implementations in high dimensions. Herein, we propose a method that combines the discrete ordinate method (DOM) with a streamline diffusion modified continuous Galerkin method to numerically solve RTE. Additionally, a phase function normalization technique was employed to dramatically reduce the instability of the DOM with fewer discrete angular points. To illustrate the accuracy and robustness of our method, the computed solutions to RTE were compared with Monte Carlo (MC) simulations when two types of sources (ideal pencil beam and Gaussian beam) and multiple optical properties were tested. Results show that with standard optical properties of human tissue, photon densities obtained using RTE are, on average, around 5% of those predicted by MC simulations in the entire/deeper region. These results suggest that this implementation of the finite element method-RTE is an accurate forward model for optical tomography in human tissues.
- Published
- 2016