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Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated bloodThe viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.
Document ID
20040112663
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Albert, M. S.
(Brigham and Women's Hospital and Harvard Medical School Boston, MA 02115, United States)
Balamore, D.
Kacher, D. F.
Venkatesh, A. K.
Jolesz, F. A.
Date Acquired
August 21, 2013
Publication Date
November 1, 2000
Publication Information
Publication: NMR in biomedicine
Volume: 13
Issue: 7
ISSN: 0952-3480
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: R29-HL57563
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Life Support Systems
Non-NASA Center

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