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Fast measurement of relaxation times by steady‐state free precession of 129 Xe in carrier agents for hyperpolarized noble gases
Author(s) -
Oregioni Alain,
Parizel Nathalie,
de Sousa Paulo Loureiro,
Grucker Daniel
Publication year - 2003
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.10476
Subject(s) - xenon , noble gas , isotopes of xenon , chemistry , relaxation (psychology) , analytical chemistry (journal) , nuclear magnetic resonance spectroscopy , steady state free precession imaging , steady state (chemistry) , nuclear magnetic resonance , chloroform , emulsion , spectroscopy , radiochemistry , chromatography , physics , magnetic resonance imaging , medicine , organic chemistry , radiology , quantum mechanics , psychology , social psychology , biochemistry
Abstract Hyperpolarized gases ( 129 Xe and 3 He) are being used increasingly in both MRI and NMR spectroscopy studies. However, it has been shown that carrier agents are required to preserve the long relaxation times of gases in biological fluids. Optimized gas transport can be achieved through controlled T 1 and T 2 measurements of 129 Xe gas at equilibrium, using the steady‐state free precession method (SSFP). The accuracy of the method was proven with the use of CuSO 4 ‐doped water samples and xenon dissolved in chloroform. The following T 1 and T 2 values were measured for xenon dissolved in a 30% intralipid emulsion: T 1 = 29 ± 3 s; T 2 = 1.0 ± 0.1 s. The values obtained in the intralipid emulsion contrast significantly with those obtained in conventional gas NMR experiments, in which it is commonly assumed that T 1 = T 2 . This highlights the importance of obtaining accurate relaxation time measurements for medical applications of hyperpolarized gases. Magn Reson Med 49:1028–1032, 2003. © 2003 Wiley‐Liss, Inc.