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Dissertation_YuningGu_yxg340_210927.pdf (6.82 MB)

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Development of Dynamic and Quantitative Proton and Oxygen-17 Magnetic Resonance Imaging Methods for Non-Invasive Assessment of Physiology in Small Laboratory Animals at High Fields

Gu, Yuning
http://rave.ohiolink.edu/etdc/view?acc_num=case1632739963852888

Abstract Details

2022, Doctor of Philosophy, Case Western Reserve University, Biomedical Engineering.
Tracking the dynamics of magnetic-resonance (MR) contrast agents in magnetic resonance imaging (MRI) studies allows non-invasive assessment of dynamic tissue properties including perfusion, permeability, and metabolism. The concentration of MR contrast agents based on paramagnetic ions can be determined from the changes in the spin-lattice (T1) and spin-spin (T2) relaxation time of water proton (1H) MR signal. However, conventional T1 and T2 mapping methods may not provide adequate temporal resolution to track the tracer dynamics, and the measurements can be prone to inhomogeneities in the main (B0) and transmit (B1+) magnetic fields. On the other side, MR contrast agents based on MR detectable isotopes, such as oxygen-17 (17O), can be tracked by hetero-nuclear MR techniques with the signal intensity directly proportional to the tracer concentration. However, the low MR sensitivity of hetero-nuclei leads to limited spatial and temporal resolution even at high B0 fields. In this work, novel quantitative 1H- and 17O-MRI methods were developed to track the dynamics of paramagnetic ions and 17O-water, respectively, to study tissue perfusion in small laboratory animals at high fields. This thesis focuses on demonstrating that the non-Cartesian encoded 1H- and 17O-MRI approaches allow delineation of perfusion profile with improved spatial and temporal resolution. Three projects are described in this thesis. First, a 2D magnetic-resonance-fingerprinting (MRF) framework was developed for rapid, simultaneous T1 and T2 quantification in mouse at 7 T. The method was demonstrated in dynamic contrast-enhanced MRI studies performed on a preclinical tumor model. Second, the MRF framework was extended to 3D for whole-brain coverage at high spatial resolution. The method was demonstrated in macaque brain covering large field-of-view (FOV) with inhomogeneous B1+ field. Finally, a dynamic 17O-MRI method using golden-means-based 3D radial acquisition combined with adaptive k-space weighted image contrast (KWIC) reconstruction was developed to assess brain-wide perfusion after a bolus injection of 17O-water in mouse model of stroke. Overall, development of these dynamic 1H- and 17O-MRI methods paves the way for non-invasive assessment of perfusion, blood-brain-barrier permeability, and oxidative metabolism in brain tissue under pathological conditions including ischemic stroke, tumor, and traumatic lesion.
Xin Yu (Advisor)
Dan Ma (Committee Chair)
Chris Flask (Committee Member)
Yunmei Wang (Committee Member)
Charlie Androjna (Committee Member)
197 p.
Biomedical Engineering
dynamic contrast-enhanced MRI; quantitative MRI; magnetic resonance fingerprinting; oxygen-17 MRI

Recommended Citations

Citations

  • Gu, Y. (2022). Development of Dynamic and Quantitative Proton and Oxygen-17 Magnetic Resonance Imaging Methods for Non-Invasive Assessment of Physiology in Small Laboratory Animals at High Fields [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1632739963852888

    APA Style (7th edition)

  • Gu, Yuning. Development of Dynamic and Quantitative Proton and Oxygen-17 Magnetic Resonance Imaging Methods for Non-Invasive Assessment of Physiology in Small Laboratory Animals at High Fields. 2022. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1632739963852888.

    MLA Style (8th edition)

  • Gu, Yuning. "Development of Dynamic and Quantitative Proton and Oxygen-17 Magnetic Resonance Imaging Methods for Non-Invasive Assessment of Physiology in Small Laboratory Animals at High Fields." Doctoral dissertation, Case Western Reserve University, 2022. http://rave.ohiolink.edu/etdc/view?acc_num=case1632739963852888

    Chicago Manual of Style (17th edition)

case1632739963852888
186
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This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.