Measurements of the persistent singlet state of N2O in blood and other solvents--potential as a magnetic tracer.

Autor: Ghosh RK; Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6056, USA. rajghosh@mail.med.upenn.edu, Kadlecek SJ, Ardenkjaer-Larsen JH, Pullinger BM, Pileio G, Levitt MH, Kuzma NN, Rizi RR
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2011 Oct; Vol. 66 (4), pp. 1177-80.
DOI: 10.1002/mrm.23119
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 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.
(Copyright © 2011 Wiley-Liss, Inc.)
Databáze: MEDLINE
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