A multisample dissolution dynamic nuclear polarization system for serial injections in small animals

作者：Krajewski Marcin; Wespi Patrick; Busch Julia; Wissmann Lukas; Kwiatkowski Grzegorz; Steinhauser Jonas; Batel Michael; Ernst Matthias; Kozerke Sebastian^*

来源：Magnetic Resonance in Medicine, 2017, 77(2): 904-910.

DOI：10.1002/mrm.26147

• dynamic nuclear polarization
• dissolution DNP
• multi-sample DNP
• metabolic imaging
• small animal

PurposeSeveral in vivo applications of dissolution dynamic nuclear polarization (DNP) require rapid successive injections of hyperpolarized substrates. Here we present the design and performance of a custom-built multisample dissolution DNP setup for small animal research.
MethodsThe DNP setup consists of a commercial wide-bore magnet charged to 3.35T, a cryostat, a 94-GHz microwave source, and a custom-built skeleton that accommodates four identical sample sticks. Each sample stick features a dissolver locked into the skeleton port and a lifter, which permits moving the sample cup out of the liquid helium bath for dissolution.
ResultsThe dissolution of the first sample was triggered after 2 hours of polarization buildup during single-shot operation of the cryostat. Thereafter, a time window of 75-90min was available to dissolve the remaining three polarized samples. The average liquid state polarization over all four sticks was measured as 18.7%2.3% for [1-13C] pyruvate 30 s after dissolution. In vivo applicability of the setup using serial injections of [1-13C] pyruvate to study cardiac metabolism in rats revealed good reproducibility.
ConclusionThe proposed four-sample DNP insert provides reproducible liquid state polarization of [1-13C] pyruvate and allows for rapid repeat injections in small animals. Magn Reson Med 77:904-910, 2017.

• 出版日期2017-2