Quintuple-tuned Surface Coil Elements

Motivation: X-nuclear MRI is used to monitor metabolic processes but requires RF coils that are individually tuned to each resonance frequency. Goal(s): To introduce a modular, flexible transmission line resonator array element for 5 resonance frequencies to enable multiple X-nuclear applications with a single coil. Approach: A quintuple-tuned shielded loop resonator (SLR5) was designed consisting of three stacked shielded loop resonators with one element for 13C and 23Na, another for 31P, and a third for 19F and 1H. Switching between nuclei was realized by PIN diodes. Results: SLR5 can be used to acquire X-nuclear signals of 5 nuclei. Impact: The SLR5 concept might facilitate the implementation of X-nuclear MRI methods for metabolic imaging in early diagnosis and monitoring of disease. SLR5 coils can be arranged favorably in coil arrays due to the inherently low coupling of SLR coils.