Magnetic resonance thermometry with superparamagnetic iron oxide nanoparticles

Thermometry based on magnetic resonance has been extensively studied due to its important application in biomedical imaging. Spin-spin relaxation time (T2) of nuclear magnetic resonance (NMR) is a highly sensitive thermometer as T2 scales with the highly temperature sensitive self-diffusion constant of fluid. In this thesis, in addition to temperature dependent self-diffusion constant of fluid, I utilize the temperature dependent magnetization of 4 nm SPIONs to improve T2 sensitivity by nearly a factor of two over self-diffusion alone in hexane between 248 K and 333 K. To extend the application of NMR T2 thermometry to engineering systems, I also investigate the temperature dependence of T2 in mineral oil, which exhibits remarkably high sensitivity (=11.7) between 273 K and 353 K. This result implies that the applications of NMR T2 thermometry in heat transfer fluids of engineering systems are promising. NMR thermometry, however, is generally not applicable to solids. Therefore, I also evaluate the potential of electron spin resonance (ESR) thermometry with SPIONs in solids between 100 K and 290 K, for potential temperature monitoring in biomedical and engineering applications. The size and concentration effects on ESR signals are studied systematically, and the results show that the temperature dependent linewidth follows a T^-2 law for 4 nm SPIONs, while the concentration of SPIONs has no impact on the temperature dependence of ESR linewidth. Combining the NMR and ESR results, I find, to obtain higher temperature sensitivity in a magnetic resonance technique using SPIONs, making the size of SPIONs as small as possible is important.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Lin, Pei-Yun

Contributors dc:contributor

• Cahill, David G

• Thermometry
• Magnetic Resonance

Statement dc:rights

• Copyright 2024 Pei-Yun Lin

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124640

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124640