Mapping Anisotropic Tissue Fiber and Microvasculature Architecture With Diffusion MRI: Application to Skeletal Muscle and White Matter

The present thesis focuses on the development of acquisition procedures and model-based analysis tools for the simultaneous characterization of anisotropic tissue fiber and microvasculature architecture in vivo, and their tissue-specific implementation in two areas of particular radiological interest: the skeletal muscle in the calf and the white matter in the brain. At the MR spatial encoding level, imaging techniques are developed with focus on the spatial resolution needs which depend on the anatomy and physiology of the imaged tissue. At the transport modeling level, a generalized framework is established to account for fiber and microvascular anisotropy by treating the tissues as musculovascular and neurovascular units. The contributions of the present work at the two above levels allow the mapping of the fiber and microvasculature architecture in skeletal muscle and white matter. The thesis addresses four problems. First, in the study of skeletal muscle fiber architecture, the idea of myofiber ellipticity is presented as a novel explanation for the asymmetry of the diffusion on the transverse plane. Second, in the study of skeletal muscle fiber architecture, a new technique, labeled, Intravoxel Partially Coherent Motion (IVPCM) technique, is formulated in order to extract information about the capillary network anisotropy. Third, in the study of the white matter fiber architecture, a diffusion acquisition technique combining multi-shot diffusion imaging with a reduced-FOV approach is developed in order to increase the spatial resolution of localized white matter anatomies and the technique is implemented in the areas of the pons and the hippocampus. Fourth, in the study of the white matter microvasculature architecture, the anisotropy of the diffusion MR signal, sensitive to microcirculatory effects, is examined to characterize the architecture of the underlying capillary network.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Karampinos, Dimitrios

Contributors dc:contributor

• Georgiadis, John G.

• Health Sciences, Radiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3347587

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83923