Multi-Directional Phase-Contrast Flow MRI in Real Time

Kollmeier, Jost M.

dc.contributor.advisor	Frahm, Jens Prof. Dr.
dc.contributor.author	Kollmeier, Jost M.
dc.date.accessioned	2021-01-28T08:24:12Z
dc.date.available	2021-01-28T08:24:12Z
dc.date.issued	2021-01-28
dc.identifier.uri	http://hdl.handle.net/21.11130/00-1735-0000-0005-155C-D
dc.identifier.uri	http://dx.doi.org/10.53846/goediss-8413
dc.language.iso	eng	de
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject.ddc	571.4	de
dc.title	Multi-Directional Phase-Contrast Flow MRI in Real Time	de
dc.type	doctoralThesis	de
dc.contributor.referee	Frahm, Jens Prof. Dr.
dc.date.examination	2020-08-31
dc.description.abstracteng	This work describes the development of a phase-contrast MRI technique that achieves multi-directional velocity quantification in real time, i.e. at high spatio-temporal resolution and without any physiological gating or data sorting. The technique exploits highly undersampled radial acquisitions with time-efficient flow encoding, a correction strategy for concomitant fields applicable to radial imaging, and an iterative solution for the non-linear image reconstruction problem. MRI is a potent and versatile imaging technique that allows to measure flow velocities, e.g. of blood flow. Unfortunately, MRI is intrinsically slow. Recent advances in real-time MRI based on radial FLASH and non-linear inversion offer high spatio-temporal resolutions and the realization of cross-sectional MRI movies. This real-time approach had been combined with uni-directional phase-contrast flow MRI that quantifies velocities only perpendicular to the imaging plane. In this work, the imaging technique is extended to more velocity dimensions. Opening with a brief overview on the basic principles of phase-contrast and real-time MRI (Chapter 2), this thesis presents the uni-directional flow technique in Chapter 3 followed by proposals for further improvements. Chapter 4 describes the development of a multi-directional extension and its optimization towards high spatio-temporal resolutions, while Chapter 5 proposes further methodological refinements. Chapter 6 addresses the technical accuracy and presents a correction strategy to eliminate background phase errors by concomitant magnetic fields applicable to radial imaging. Preliminary in vivo results demonstrated in Chapter 7 include cardiac flow imaging with velocity quantification in all three directions at less than 2 x 2 mm² pixel-size and more than 60 frames per second. The novel MRI technique developed in this thesis increases the potential of MRI based cross-sectional velocimetry.	de
dc.contributor.coReferee	Enderlein, Jörg Prof. Dr.
dc.contributor.thirdReferee	Scheffler, Klaus Prof. Dr.
dc.subject.eng	real-time MRI	de
dc.subject.eng	phase-contrast MRI	de
dc.subject.eng	radial MRI	de
dc.subject.eng	model-based reconstruction	de
dc.subject.eng	radial Maxwell correction	de
dc.subject.eng	multi-directional flow	de
dc.subject.eng	4D flow	de
dc.subject.eng	velocimetry	de
dc.subject.eng	Karman vortex shedding	de
dc.subject.eng	blood flow	de
dc.subject.eng	CSF flow	de
dc.subject.eng	3D flow	de
dc.identifier.urn	urn:nbn:de:gbv:7-21.11130/00-1735-0000-0005-155C-D-7
dc.affiliation.institute	Göttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB)	de
dc.subject.gokfull	Biologie (PPN619462639)	de
dc.identifier.ppn	1745980636

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Das Dokument erscheint in:

GGNB - Göttinger Graduiertenzentrum für Neurowissenschaften, Biophysik und molekulare Biowissenschaften [1112]
GGNB - Göttingen Graduate Center for Neurosciences, Biophysics and Molecular Biosciences

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