Surface dielectric resonator for in vivo EPR measurements

• Published in: Journal of magnetic resonance (1997) 2024-05, Vol.362, p.107690-107690, Article 107690
• Main Authors: Petryakov, Sergey V., Kmiec, Maciej M., Ubert, Conner S., Kassey, Victor B., Schaner, Philip E., Kuppusamy, Periannan
• Format: Article
• Language: English
• Subjects: Electromagnetic Fields; Electron Spin Resonance Spectroscopy - instrumentation; Electron Spin Resonance Spectroscopy - methods; Equipment Design; Oximetry - instrumentation; Oximetry - methods; Phantoms, Imaging; Reproducibility of Results
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2024.107690

[Display omitted] •A novel surface dielectric resonator with flexible connector.•Suitable for in vivo electron paramagnetic resonance spectroscopy.•Constructed using a selected ceramic material.•Works at 1.15 GHz in continuous-wave mode.•Designed to be critically coupled and working with lossy samples. This research report describes a novel surface dielectric resonator (SDR) with a flexible connector for in vivo electron paramagnetic resonance (EPR) spectroscopy. Contrary to the conventional cavity or surface loop-gap resonators, the newly developed SDR is constructed from a ceramic dielectric material, and it is tuned to operate at the L-band frequency band (1.15 GHz) in continuous-wave mode. The SDR is designed to be critically coupled and capable of working with both very lossy samples, such as biological tissues, and non-lossy materials. The SDR was characterized using electromagnetic field simulations, assessed for sensitivity with a B1 field-perturbation method, and validated with tissue phantoms using EPR measurements. The results showed remarkably higher sensitivity in lossy tissue phantoms than the previously reported multisegment surface-loop resonators. The new SDR can provide potential new insights for advancements in the application of in vivo EPR spectroscopy for biological measurements, including clinical oximetry.