Initial in vivo rodent sodium and proton MR imaging at 21.1 T

Schepkin, Victor D.; Brey, William W.; Gor'kov, Peter L.; Grant, Samuel C.

doi:10.1016/j.mri.2009.10.002

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Volume 28, Issue 3 , Pages 400-407, April 2010

Initial in vivo rodent sodium and proton MR imaging at 21.1 T

Victor D. Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005, USA
- Corresponding author. Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA. Tel.: +1 850 645 7357; fax: +1 850 644 1366.
William W. Brey
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005, USA
Peter L. Gor'kov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005, USA
Samuel C. Grant
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005, USA
- Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310-4005, USA

Received 22 June 2009; received in revised form 14 September 2009; accepted 12 October 2009. published online 04 January 2010.

Abstract

The first in vivo sodium and proton magnetic resonance (MR) images and localized spectra of rodents were attained using the wide bore (105 mm) high resolution 21.1-T magnet, built and operated at the National High Magnetic Field Laboratory (Tallahassee, FL, USA). Head images of normal mice (C57BL/6J) and Fisher rats (∼250 g) were acquired with custom designed radiofrequency probes at frequencies of 237/900 MHz for sodium and proton, respectively. Sodium MR imaging resolutions of ∼0.125 μl for mouse and rat heads were achieved by using a 3D back-projection pulse sequence. A gain in SNR of ∼3 for sodium and ∼2 times for proton were found relative to corresponding MR images acquired at 9.4 T. 3D Fast Low Angle Shot (FLASH) proton mouse images (50×50×50 μm³) were acquired in 90 min and corresponding rat images (100×100×100 μm³) within a total time of 120 min. Both in vivo large rodent MR imaging and localized spectroscopy at the extremely high field of 21.1 T are feasible and demonstrate improved resolution and sensitivity valuable for structural and functional brain analysis.

Keywords: High magnetic field, In vivo rodent, MRI, Sodium, Localized spectroscopy