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

摘要

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.