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Two‐component diffusion tensor MRI of isolated perfused hearts
Author(s) -
Hsu Edward W.,
Buckley David L.,
Bui Jonathan D.,
Blackband Stephen J.,
Forder John R.
Publication year - 2001
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.1138
Subject(s) - diffusion mri , diffusion , anisotropy , anisotropic diffusion , nuclear magnetic resonance , component (thermodynamics) , orientation (vector space) , tensor (intrinsic definition) , thermal diffusivity , chemistry , physics , mathematics , magnetic resonance imaging , geometry , medicine , optics , thermodynamics , radiology
Abstract Nonmonoexponential MR diffusion decay behavior has been observed at high diffusion‐weighting strengths for cell aggregates and tissues, including the myocardium; however, implications for myocardial MR diffusion tensor imaging are largely unknown. In this study, a slow‐exchange‐limit, two‐component diffusion tensor model was fitted to diffusion‐weighted images obtained in isolated, perfused rat hearts. Results indicate that there are at least two distinct components of anisotropic diffusion, characterized by a “fast” component whose principal diffusivity is comparable to that of the perfusate, and a highly anisotropic “slow” component. It is speculated that the two components correspond to tissue compartments and have a general agreement with the orientations of anisotropy, or fiber orientations, in the myocardium. Moreover, consideration of previous studies of myocardial diffusion suggests that the presently observed fast component may likely be dominated by diffusion in the vascular space, whereas the slow component may include the intracellular and interstitial compartments. The implications of the results for myocardial fiber orientation mapping and limitations of the current two‐component model used are also discussed. Magn Reson Med 45:1039–1045, 2001. © 2001 Wiley‐Liss, Inc.