Improvement of 19F MR image uniformity in a mouse model of cellular therapy using inductive coupling
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Improve 19F magnetic resonance imaging uniformity of perfluorocarbon (PFC)-labeled cells by using a secondary inductive resonator tuned to 287 MHz to enhance the induced radio frequency (RF) magnetic field (B1) at 7.05 T.
Materials and methods
Following Faraday’s induction law, the sign of induced B1 made by the secondary resonator can be changed depending on the tuning of the resonator. A secondary resonator located on the opposite side of the phantom of the 19F surface coil can be shown to enhance or subtract the induced B1 field, depending upon its tuning.
The numerical simulation results of rotating transmit B1 magnitude (|B 1 + |) and corresponding experimental 19F images were compared without and with the secondary resonator. With the secondary resonator tuned to 287 MHz, improvements of |B 1 + | and 19F image uniformity were demonstrated. The use of the secondary resonator improved our ability to visualize transplanted cell location non-invasively over a period of 6 weeks.
The secondary resonator tuned to enhance the induced B1 results in improved image uniformity in a pre-clinical application, enabling cell tracking of PFC-labeled cells with the secondary resonator.
KeywordsResonator Fluorine MR 19F MR Computational modeling Perfluorocarbon Polyethylene glycol
We thank Charity Stagg, Xiao-Hong Li, Eric Nimako, and Jessica Dewar from the CBER/FDA veterinary staff for their assistance with animal surgeries and imaging.
BSP: conceptualization, data curation, formal analysis, methodology, investigation, resources, validation, visualization, and writing. GM: data curation, methodology, formal analysis, and validation. WTK: data curation, methodology, formal analysis, SSR: methodology, formal analysis, and resources. MM: data curation, methodology, and formal analysis. JL: data curation, methodology, and formal analysis. KS: conceptualization and supervision. BM: conceptualization, investigation, project administration and supervision.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
The mention of commercial products, their sources, or their use in connection with material reported herein is not to be construed as either an actual or implied endorsement of such products by the Department of Health and Human Services.
All procedures performed in studies were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
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