| Autor: |
Ghosh, R. K., Kadlecek, S. J., Ardenkjaer-Larsen, J. H., Pullinger, B. M., Pileio, G., Levitt, M. H., Kuzma, N. N., Rizi, R. R. |
| Zdroj: |
Magnetic Resonance in Medicine; Oct2011, Vol. 66 Issue 4, p1177-1180, 4p |
| Abstrakt: |
The development of hyperpolarized tracers has been limited by short nuclear polarization lifetimes. The dominant relaxation mechanism for many hyperpolarized agents in solution arises from intramolecular nuclear dipole-dipole coupling modulated by molecular motion. It has been previously demonstrated that nuclear spin relaxation due to this mechanism can be removed by storing the nuclear polarization in long-lived, singlet-like states. In the case of N2O, storing the polarization of the nitrogen nuclei has been shown to substantially increase the polarization lifetime. The feasibility of utilizing N2O as a tracer is investigated by measuring the singlet-state lifetime of the N2O when dissolved in a variety of solvents including whole blood. Comparison of the singlet lifetime to longitudinal relaxation and between protonated and deuterated solvents is consistent with the dominance of spin-rotation relaxation, except in the case of blood. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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