OnlyParahydrogen SpectrosopY (OPSY) pulse sequences - One does not fit all

Andrey N Pravdivtsev; Frank Sönnichsen; Jan-Bernd Hövener

doi:10.1016/j.jmr.2018.10.006

OnlyParahydrogen SpectrosopY (OPSY) pulse sequences - One does not fit all

J Magn Reson. 2018 Dec:297:86-95. doi: 10.1016/j.jmr.2018.10.006. Epub 2018 Oct 10.

Authors

Andrey N Pravdivtsev¹, Frank Sönnichsen², Jan-Bernd Hövener³

Affiliations

¹ Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Kiel, Germany. Electronic address: andrey.pravdivtsev@rad.uni-kiel.de.
² Faculty of Mathematics and Natural Sciences, Chemistry Section, Kiel University, Kiel, Germany.
³ Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Kiel, Germany.

PMID: 30366223
DOI: 10.1016/j.jmr.2018.10.006

Abstract

The hyperpolarization of nuclear spins using parahydrogen is an interesting effect that allows to increase the magnetic resonance signal by several orders of magnitude. Known as ParaHydrogen And Synthesis Allow Dramatically Enhanced Nuclear Alignment (PASADENA) and ParaHydrogen Induced Polarization (PHIP), the method was successfully used for in vitro analysis and in vivo imaging. In this contribution, we investigated four known and four new variants of Only Parahydrogen SpectroscopY (OPSY) sequences (Aguilar et al., 2007) with respect to the selective preparation of hyperpolarized NMR signal and background suppression. Depending on the method chosen, either anti-phase, in-phase or a mixture of both signals are obtained: anti-phase signals are beneficial to identify hyperpolarized signals and the structure or J-coupling constants; in-phase signals are useful for imaging applications or when the lines are broad. This comprehensive overview of sequences new and old facilitates selecting the right sequence for the task at hand.

Keywords: Background suppression; Hydrogenation; Hyperpolarization; NMR; OPSY; PASADENA; PHIP; Para-hydrogen; Singlet order; Spectroscopy.

Publication types

Research Support, Non-U.S. Gov't