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On the oxygenation‐dependent 129 Xe T 1 in blood
Author(s) -
Wolber Jan,
Cherubini Andrea,
Leach Martin O.,
Bifone Angelo
Publication year - 2000
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/1099-1492(200006)13:4<234::aid-nbm632>3.0.co;2-k
Subject(s) - oxygenation , hemoglobin , chemistry , oxygen , arterial blood , xenon , relaxation (psychology) , venous blood , blood oxygenation , nuclear magnetic resonance , medicine , biochemistry , physics , organic chemistry , radiology , functional magnetic resonance imaging
The spin‐lattice relaxation time, T 1 , of hyperpolarized 129 Xe in blood is sensitive to blood oxygenation. In particular, it has been shown that 129 Xe T 1 is shorter in venous blood than in arterial blood. We have studied the T 1 of hyperpolarized 129 Xe dissolved in human blood as a function of blood oxygenation level, sO 2 , in the physiological oxygenation range. We show that the 129 Xe relaxation rate, $T_{1}^{-1}$ , varies in a nonlinear fashion as a function of sO 2 . This finding suggests that direct interaction of xenon with the paramagnetic heme group of deoxyhemoglobin is not the dominant oxygenation‐dependent relaxation mechanism for 129 Xe in blood. These results corroborate the idea that the oxygenation‐dependence of 129 Xe T 1 is determined by conformational changes of hemoglobin induced by oxygen binding. Copyright © 2000 John Wiley & Sons, Ltd.