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

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.

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.