A large volume double channel 1H-X RF probe for hyperpolarized magnetic resonance at 0.0475 T.

In this work we describe a large volume 340 mL (1)H-X magnetic resonance (MR) probe for studies of hyperpolarized compounds at 0.0475 T. (1)H/(13)C and (1)H/(15)N probe configurations are demonstrated with the potential for extension to (1)H/(129)Xe. The primary applications of this probe are preparation and quality assurance of (13)C and (15)N hyperpolarized contrast agents using PASADENA (parahydrogen and synthesis allow dramatically enhanced nuclear alignment) and other parahydrogen-based methods of hyperpolarization. The probe is efficient and permits 62 μs (13)C excitation pulses at 5.3 W, making it suitable for portable operation. The sensitivity and detection limits of this probe, tuned to (13)C, are compared with a commercial radio frequency (RF) coil operating at 4.7 T. We demonstrate that low field MR of hyperpolarized contrast agents could be as sensitive as conventional high field detection and outline potential improvements and optimization of the probe design for preclinical in vivo MRI. PASADENA application of this low-power probe is exemplified with (13)C hyperpolarized 2-hydroxyethyl propionate-1-(13)C,2,3,3-d(3).