High-resolution hyperpolarized in vivo metabolic 13C spectroscopy at low magnetic field (48.7 mT) following murine tail-vein injection

High-resolution C-13 NMR spectroscopy of hyperpolarized succinate-1-C-13-2,3-d(2) is reported in vitro and in vivo using a clinical-scale, biplanar (80 cm-gap) 48.7 mT permanent magnet with a high homogeneity magnetic field. Non-localized C-13 NMR spectra were recorded at 0.52 MHz resonance frequency over the torso of a tumor-bearing mouse every 2 s. Hyperpolarized C-13 NMR signals with linewidths of similar to 3 Hz (corresponding to similar to 6 ppm) were recorded in vitro (2 mL in a syringe) and in vivo (over a mouse torso). Comparison of the full width at half maximum (FWHM) for C-13 NMR spectra acquired at 48.7 mT and at 4.7 T in a small-animal MRI scanner demonstrates a factor of similar to 12 improvement for the C-13 resonance linewidth attainable at 48.7 mT compared to that at 4.7 Tin vitro. C-13 hyperpolarized succinate-1-C-13 resonance linewidths in vivo are at least one order of magnitude narrower at 48.7 mT compared to those observed in high-field (>= 3 T) studies employing HP contrast agents. The demonstrated high -resolution C-13 in vivo spectroscopy could be useful for high -sensitivity spectroscopic studies involving monitoring HP agent uptake or detecting metabolism using HP contrast agents with sufficiently large C-13 chemical shift differences. (C) 2017 Elsevier Inc. All rights reserved.