Autonomous cryogenic RF receive coil for 13C imaging of rodents at 3 T

Juan Diego Sánchez-Heredia*, Rafael Antonio Baron, Esben Søvsø Szocska Hansen, Christoffer Laustsen, Vitaliy Zhurbenko, Jan Henrik Ardenkjær-Larsen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Purpose: To develop an autonomous, in-bore, MR-compatible cryostat cooled with liquid nitrogen that provides full-day operation, and to demonstrate that the theoretical signal-to-noise benefit can be achieved for 13C imaging at 3 T (32.13 MHz).
Methods: The cryogenic setup uses a vacuum-insulated fiberglass cryostat, which indirectly cools a cold finger where the RF coil is attached. The cryostat was evacuated before use and had a reservoir of liquid nitrogen for full-day operation. A 30 × 40 mm2 copper coil was mounted inside the cryostat with a 3-mm distance to the sample. Two examples of in vivo experiments of rat brain metabolism after a hyperpolarized [1-13C]pyruvate injection are reported. Results: A coil Q-factor ratio of Q88K/Q290K = 550/280 was obtained, and the theoretical SNR enhancement was verified with MR measurements. We achieved a coil temperature of 88 K and a preamplifier temperature of 77 K. A 2-fold overall SNR enhancement was achieved, compared with the best case at room temperature. The thermal performance of the coil was adequate for in vivo experiments, with an autonomy of 5 hours consuming 6 L of LN2, extendable to over 12 hours by LN2 refilling.
Conclusion: Cryogenic surface coils can be highly beneficial for 13C imaging, provided that the coil-to-sample distance remains short. An autonomous, in-bore cryostat was developed that achieved the theoretical improvement in SNR.
Original languageEnglish
JournalMagnetic Resonance in Medicine
Volume84
Pages (from-to)497–508
ISSN0740-3194
DOIs
Publication statusPublished - 2020

Keywords

  • 13C MRI
  • Cryogenic
  • Hyperpolarization
  • RF coil
  • SNR

Cite this