| Autor: |
R K, Ghosh, S J, Kadlecek, J H, Ardenkjaer-Larsen, B M, Pullinger, G, Pileio, M H, Levitt, N N, Kuzma, R R, Rizi |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
Magnetic resonance in medicine. 66(4) |
| ISSN: |
1522-2594 |
| Popis: |
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 N(2)O, storing the polarization of the nitrogen nuclei has been shown to substantially increase the polarization lifetime. The feasibility of utilizing N(2)O as a tracer is investigated by measuring the singlet-state lifetime of the N(2)O 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. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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