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@PHDTHESIS{Chen:1009543,
author = {Chen, Qingping},
othercontributors = {Shah, Nadim Joni and Veselinovic, Tanja},
title = {{D}evelopment and implementation of accelerated
multiple-quantum-filtered sodium magnetic resonance imaging
using compressed sensing at ultra-high field},
school = {Rheinisch-Westfälische Technische Hochschule Aachen},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2025-03519},
pages = {1 Online-Ressource : Illustrationen},
year = {2025},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, Rheinisch-Westfälische Technische
Hochschule Aachen, 2025},
abstract = {Sodium (23Na) plays a critical role in cellular metabolic
processes via the regulation of the sodium-potassium pump,
which maintains a large gradient between intracellular and
extracellular sodium concentrations at the expense of
energy. Cellular dysfunction can lead to an elevated
intracellular sodium concentration, whereas the
extracellular sodium concentration remains primarily
unchanged due to tissue perfusion. Therefore, intracellular
sodium, as a direct link to cell integrity and tissue
viability, promises means for an insight into pathological
processes.Conventional sodium Magnetic Resonance Imaging
(MRI) with a single radiofrequency pulse can only detect
total sodium. Based on the quadrupolar nature of the sodium
nucleus, an advanced technique, Multiple-Quantum-Filtered
(MQF) sodium MRI, is proposed to monitor restricted (mainly
intracellular) sodium. However, the clinical application of
MQF sodium MRI is hampered by the relatively low image
quality and associated long acquisition times. This thesis
aims to mitigate the limitations of MQF sodium MRI by
exploiting two aspects: data acquisition and image
reconstruction. Regarding data acquisition, this thesis
optimised the enhanced Simultaneous Single-quantum and
Triple-quantum-filtered imaging of 23NA (SISTINA) sequence
using a highly efficient non-Cartesian sampling scheme.
Qualitative validation of this sequence optimisation was
conducted by comparing the optimised sequence with a
conventional enhanced SISTINA sequence in phantom
measurements at 7T. The optimisation greatly improved the
visual performance of ultra-short-echo-time images, while
maintaining the visual quality of MQF images and introducing
incoherence in raw data for the application of Compressed
Sensing (CS) acceleration. Regarding image reconstruction,
this thesis applied CS to accelerate enhanced SISTINA
acquisitions by exploiting image sparsity to compensate for
incoherent under sampling artefacts. Quantitative validation
of the CS acceleration was performed by comparing the under
sampled CS-based reconstructions with fully sampled and
under sampled standard Non-Uniform Fast Fourier Transform
(NUFFT) reconstructions in both phantom and in vivo
measurements at 7T. Compared to NUFFT, CS accelerated
enhanced SISTINA by up to twofold at 7T in this study with
reduced noise levels, while maintaining primary structural
information, reasonable weightings towards total and
compartmental sodium and relatively accurate in vivo
quantification.},
cin = {535000-5 ; 934010},
ddc = {610},
cid = {$I:(DE-82)535000-5_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2025-03519},
url = {https://publications.rwth-aachen.de/record/1009543},
}
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