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Exploring lung function with hyperpolarized 129 Xe nuclear magnetic resonance
Author(s) -
Ruppert Kai,
Mata Jaime F.,
Brookeman James R.,
Hagspiel Klaus D.,
Mugler John P.
Publication year - 2004
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.10736
Subject(s) - xenon , nuclear magnetic resonance , chemistry , hyperpolarization (physics) , lung , isotopes of xenon , lung volumes , gaseous diffusion , magnetic resonance imaging , magnetization transfer , diffusion , polarization (electrochemistry) , nuclear magnetic resonance spectroscopy , physics , radiology , medicine , thermodynamics , organic chemistry , electrode
With the use of polarization‐transfer pulse sequences and hyperpolarized 129 Xe NMR, gas exchange in the lung can be measured quantitatively. However, harnessing the inherently high sensitivity of this technique as a tool for exploring lung function requires a fundamental understanding of the xenon gas‐exchange and diffusion processes in the lung, and how these may differ between healthy and pathological conditions. Toward this goal, we employed NMR spectroscopy and imaging techniques in animal models to investigate the dependence of the relative xenon gas exchange rate on the inflation level of the lung and the tissue density. The spectroscopic results indicate that gas exchange occurs on a time scale of milliseconds, with an average effective diffusion constant of about 3.3 × 10 −6 cm 2 /s in the lung parenchyma. Polarization‐transfer imaging pulse sequences, which were optimized based on the spectroscopic results, detected regionally increased gas‐exchange rates in the lung, indicative of increased tissue density secondary to gravitational compression. By exploiting the gas‐exchange process in the lung to encode physiologic parameters, these methods may be extended to noninvasive regional assessments of lung‐tissue density and the alveolar surface‐to‐volume ratio, and allow lung pathology to be detected at an earlier stage than is currently possible. Magn Reson Med 51:676–687, 2004. © 2004 Wiley‐Liss, Inc.