Title
Modelling anomalous diffusion using fractional Bloch-Torrey equations on approximate irregular domains.
Abstract
Diffusion-weighted imaging is an in vivo, non-invasive medical diagnosis technique that uses the Brownian motion of water molecules to generate contrast in the image and therefore reveals exquisite details about the complex structures and adjunctive information of its surrounding biological environment. Recent work highlights that the diffusion-induced magnetic resonance imaging signal loss deviates from the classic monoexponential decay. To investigate the underlying mechanism of this deviated signal decay, diffusion is re-examined through the Bloch–Torrey equation by using fractional calculus with respect to both time and space. In this study, we explore the influence of the complex geometrical structure on the diffusion process. An effective implicit alternating direction method implemented on approximate irregular domains is proposed to solve the two-dimensional time–space Riesz fractional partial differential equation with Dirichlet boundary conditions. This scheme is proved to be unconditionally stable and convergent. Numerical examples are given to support our analysis. We then applied the proposed numerical scheme with some decoupling techniques to investigate the magnetisation evolution governed by the time–space fractional Bloch–Torrey equations on irregular domains.
Year
DOI
Venue
2018
10.1016/j.camwa.2017.08.032
Computers & Mathematics with Applications
Keywords
Field
DocType
Irregular domains,Finite difference method,Fractional Bloch–Torrey equations,Stability,Convergence
Diffusion process,Mathematical optimization,Mathematical analysis,Spacetime,Decoupling (cosmology),Dirichlet boundary condition,Fractional calculus,Brownian motion,Partial differential equation,Anomalous diffusion,Mathematics
Journal
Volume
Issue
ISSN
75
1
0898-1221
Citations 
PageRank 
References 
1
0.36
6
Authors
5
Name
Order
Citations
PageRank
Shanlin Qin1121.33
F. Liu241942.86
Ian Turner31016122.29
Qianqian Yang415210.71
Q. Yu5453.73