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Title: New MRI contrast agents through spin exchange optical pumping of noble gases with a nuclear electric quadrupole moment
Author: Six, Joseph
ISNI:       0000 0004 5361 0494
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2014
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Hyperpolarized 83Kr has previously demonstrated MRI contrast that is sensitive to the chemical composition of the surface in a porous model system. One-dimensional nuclear magnetic resonance spectroscopy of hyperpolarized 83Kr has also revealed distinctive longitudinal relaxation times from selected regions of an ex vivo rat lung originating from differences in surface to volume ratio. However, at the time, MRI using longitudinal relaxation for contrast was not attempted due to limited signal intensities. Methodological advances of the spin exchange optical pumping process have led to a substantial increase in the 83Kr hyperpolarization and the resulting signal intensity. This methodology originates from a below-ambient pressure hyperpolarization technique explored and developed in this work. Using the improved methodology for spin exchange optical pumping of isotopically enriched 83Kr has resolved anatomical details of ex vivo rodent lungs using hyperpolarized 83Kr MRI for the first time. Different 83Kr longitudinal relaxation times were found between the main bronchi and the parenchymal regions of the lung. The T1 weighted hyperpolarized 83Kr MRI provided the first demonstration of surface quadrupolar relaxation pulmonary MRI contrast. Novel hyperpolarization techniques of 129Xe have also been explored resulting a study into the combustion process of methane. Using 129Xe as a probe into the combustion process permitted the first in situ MRI of combustion and enabled spatial-velocity profiles.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: WN Radiology. Diagnostic imaging