Improvement of 19F MR image uniformity in a mouse model of cellular therapy using inductive coupling

Objective Improve 19 F 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 ( B 1 ) at 7.05 T. Materials and methods Following Faraday’s induction law, the sign of induced B 1 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 19 F surface coil can be shown to enhance or subtract the induced B 1 field, depending upon its tuning. Results The numerical simulation results of rotating transmit B 1 magnitude (| B 1 + |) and corresponding experimental 19 F images were compared without and with the secondary resonator. With the secondary resonator tuned to 287 MHz, improvements of | B 1 + | and 19 F 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. Conclusion The secondary resonator tuned to enhance the induced B 1 results in improved image uniformity in a pre-clinical application, enabling cell tracking of PFC-labeled cells with the secondary resonator.