MaColumnSolversAxdt

Chair for Computer Aided Medical Procedures & Augmented Reality
Lehrstuhl für Informatikanwendungen in der Medizin & Augmented Reality

Thesis: Accelerating solvers for column-wise blocked large-scale linear systems used in anisotropic X-ray dark-field tomography

Thesis by:
Advisor: Tobias Lasser
Supervision by: Matthias Wieczorek

Abstract

X-ray grating interferometry enables the simultaneous acquisition of absorption contrast, phase contrast and dark-field contrast. The directionally dependent dark-field data allows the tomographic reconstruction of anisotropic scattering coefficients inside the sample. This allows the recovery of structural orientations without the need to explicitly resolve them in the X-ray detector. The anisotropic scattering coefficients can be represented as spherical functions, such as spherical harmonics. Based on a closed-form spherical harmonics based forward model, the anisotropic dark-field data can be reconstructed in three dimensions. We refer to this technique as "Anisotropic X-ray Dark-field Tomography", or in short AXDT.

Tasks

Subject of this thesis is the acceleration of solving methods used in Anisotropic X-ray Dark-field Tomography (AXDT). The aim is to investigate accelerated solving approaches of the column-wise blocked large-scale linear system employed in AXDT. Acceleration methods, such as preconditioning, are to be investigated and implemented in our existing C++ reconstruction framework, with a quantitative evaluation of their performance compared to a basic conjugate gradient method.

Requirements

Scientific programming, C++

Contact


ProjectForm
Title: Accelerating solvers for column-wise blocked large-scale linear systems used in anisotropic X-ray dark-field tomography
Abstract: X-ray grating interferometry enables the simultaneous acquisition of absorption contrast, phase contrast and dark-field contrast. The directionally dependent dark-field data allows the tomographic reconstruction of anisotropic scattering coefficients inside the sample. This allows the recovery of structural orientations without the need to explicitly resolve them in the X-ray detector. The anisotropic scattering coefficients can be represented as spherical functions, such as spherical harmonics. Based on a closed-form spherical harmonics based forward model, the anisotropic dark-field data can be reconstructed in three dimensions. We refer to this technique as "Anisotropic X-ray Dark-field Tomography", or in short AXDT.
Student:  
Director: Tobias Lasser
Supervisor: Matthias Wieczorek
Type: DA/MA/BA
Area: Medical Imaging
Status: open
Start: 2017/11/15
Finish:  
Thesis (optional):  
Picture:  


Edit | Attach | Refresh | Diffs | More | Revision r1.2 - 20 Dec 2016 - 07:52 - TobiasLasser