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Multiple‐exchange‐time xenon polarization transfer contrast (MXTC) MRI: Initial results in animals and healthy volunteers
Author(s) -
Dregely Isabel,
Ruset Iulian C.,
Mata Jaime F.,
Ketel Jeffrey,
Ketel Steve,
Distelbrink Jan,
Altes Talissa A.,
Mugler John P.,
Wilson Miller G.,
William Hersman F.,
Ruppert Kai
Publication year - 2012
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.23066
Subject(s) - xenon , supine position , lung , lung volumes , nuclear medicine , contrast (vision) , magnetic resonance imaging , nuclear magnetic resonance , chemistry , medicine , radiology , physics , optics , organic chemistry
Hyperpolarized xenon‐129 is a noninvasive contrast agent for lung MRI, which upon inhalation dissolves in parenchymal structures, thus mirroring the gas‐exchange process for oxygen in the lung. Multiple‐exchange‐time xenon polarization transfer contrast (MXTC) MRI is an implementation of the XTC MRI technique in four dimensions (three spatial dimensions plus exchange time). The aim of this study was to evaluate the sensitivity of MXTC MRI for the detection of microstructural deformations of the healthy lung in response to gravity‐induced tissue compression and the degree of lung inflation. MXTC MRI was performed in four rabbits and in three healthy human volunteers. Two lung function parameters, one related to tissue‐ to alveolar‐volume ratio and the other to average septal‐wall thickness, were determined regionally. A significant gradient in MXTC MRI parameters, consistent with gravity‐induced lung tissue deformation in the supine imaging position, was found at low lung volumes. At high lung volumes, parameters were generally lower and the gradient in parameter values was less pronounced. Results show that MXTC MRI permits the quantification of subtle changes in healthy lung microstructure. Further, only structures participating in gas exchange are represented in MXTC MRI data, which potentially makes the technique especially sensitive to pathological changes in lung microstructure affecting gas exchange. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.