Three-frequency RF coil designed for optimized imaging of hyperpolarized, 13C-labeled compounds.

Imaging exams involving hyperpolarized, (13)C-labeled compounds require novel RF coils for efficient signal utilization. While (13)C coils are required for mapping the spatial distribution of the hyperpolarized compounds, imaging/pulsing at different frequencies is also needed for scan setup steps prior to the image acquisition. Imaging/pulsing at the (1)H frequency is typically used for anatomical localization and shimming. Flip angle (FA) calibration, which is difficult or impossible to achieve at the (13)C frequency, can be accurately performed at the (23)Na frequency using the natural abundance signal that exists in any living tissue. We demonstrate here a single RF resonant structure that is capable of operating linearly at the (1)H and (23)Na frequencies for scan setup steps, and in quadrature at the (13)C frequency for imaging. Images at the three resonant frequencies of this coil are presented from an exam involving hyperpolarized (13)C compounds in vivo. (c) 2008 Wiley-Liss, Inc.