Single-input double-tuned birdcage coil with identical B1 field profile for 1H and 19F imaging

Introduction: A double tuned birdcage coil was widely studied for its good field homogeneity and convenience in support of a heteronuclear MRI experiment. Since the birdcage coil is a multi-mode resonator with complicated electrical property, its double-tuned version is often designed to achieve the required frequency shift by geometrically rearranging coil legs, adding new tunable elements to specific legs, or varying shield size [1-3]. We proposed a novel design of double-tuned birdcage coil by inserting a secondary resonator in the feeding circuit without changing the structure of birdcage coil. The frequency response and magnetic field distribution of the coil were measured followed by in vivo demonstration. Furthermore, we experimentally showed that our coil is able to be integrated with active decoupling technique [4].