Date of Award

Summer 8-22-2026

Document Type

Dissertation

Degree Name

Ph.D. in Chemistry and Biochemistry

Organizational Unit

College of Natural Science and Mathematics, Chemistry and Biochemistry

First Advisor

Sandra S. Eaton

Second Advisor

Gareth R. Eaton

Third Advisor

Dali Sun

Fourth Advisor

Scott Horowitz

Fifth Advisor

Brian Majestic

Sixth Advisor

Brady Worrell

Copyright Statement / License for Reuse

All Rights Reserved
All Rights Reserved.

Keywords

Electron paramagnetic resonance (EPR), High-sensitivity, In vivo imaging, Low frequency, Magnetic resonance, Preclinical

Abstract

Magnetic resonance is one of the most generally useful scientific techniques. New horizons of understanding are revealed as technological advances make possible explorations of nuclear spins and electron spins at higher and lower magnetic fields and electromagnetic frequencies. While the greatest current effort is on ever higher magnetic fields and microwave frequencies, both in nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), the Eaton lab focusses on developing high signal-to-noise performance EPR at low microwave frequencies. EPR provides information about O2, pH, viscosity, glutathione concentrations, and reactive oxygen species in living organisms that MRI cannot. To yield clinically or preclinically relevant images good signal-to-noise (S/N) is required. It is hypothesized that new EPR instrumentation is needed for this at 1 GHz which should provide the required S/N and penetrate the body to the desired depth.

The Eaton lab initiated and developed pulsed microwave and rapid magnetic field scan imaging at 250 MHz and then 700 MHz. The focus of this thesis is the step from 700 MHz to 1 GHz. The application of rapid scan imaging at 1 GHz to preclinical imaging of mouse lungs and diabetic wound healing at the Anschutz Medical Center has been demonstrated.

To further boost the signal to noise a technique that rapidly modulates the magnetic field called ‘rapid scan’ is employed. A key feature of the rapid scan spectrometer and imager is the achievement of the highest S/N of any low-frequency EPR spectrometer that has been reported. Pulsed spectrometers have advantages for oximetry experiments in particular, so an initial investigation was done into the design of this type of spectrometer at 1 GHz. Together, these rapid scan and pulse spectrometers will establish a foundation for the development of future high-sensitivity preclinical and later clinical EPR imaging.

Construction of both of these instruments required extensive computer programing in MATLAB and interfacing high-performance digitizers to the EPR signal data-acquisition path. The codes produced are provided.

Copyright Date

8-2026

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Rights Holder

Tanden A. Hovey

Provenance

Received from ProQuest

File Format

application/pdf

Language

English (eng)

Extent

259 pgs

File Size

3.8 MB

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