A double-tuned ¹ H/³¹ P coil for rabbit heart metabolism detection at 3 T

Magnetic resonance imaging (MRI)/magnetic resonance spectroscopy (MRS) employing proton nuclear resonance has emerged as a pivotal modality in clinical diagnostics and fundamental research. Nonetheless, the scope of MRI/MRS extends beyond protons, encompassing nonproton nuclei that offer enhanced metabolic insights. A notable example is phosphorus-31 (³¹ P) MRS, which provides valuable information on energy metabolites within the skeletal muscle and cardiac tissues of individuals affected by diabetes. This study introduces a novel double-tuned coil tailored for ¹ H and ³¹ P frequencies, specifically designed for investigating cardiac metabolism in rabbits. The proposed coil design incorporates a butterfly-like coil for ³¹ P transmission, a four-channel array for ³¹ P reception, and an eight-channel array for ¹ H reception, all strategically arranged on a body-conformal elliptic cylinder. To assess the performance of the double-tuned coil, a comprehensive evaluation encompassing simulations and experimental investigations was conducted. The simulation results demonstrated that the proposed ³¹ P transmit design achieved acceptable homogeneity and exhibited comparable transmit efficiency on par with a band-pass birdcage coil. In vivo experiments further substantiated the coil's efficacy, revealing that the rabbit with experimentally induced diabetes exhibited a lower phosphocreatine/adenosine triphosphate ratio compared with its normal counterpart. These findings emphasize the potential of the proposed coil design as a promising tool for investigating the therapeutic effects of novel diabetes drugs within the context of animal experimentation. Its capability to provide detailed metabolic information establishes it as an indispensable asset within this realm of research.