| The tensor distribution function. | |
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MedLine Citation:
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PMID: 19097208 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Diffusion weighted magnetic resonance imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of six directions, second-order tensors (represented by three-by-three positive definite matrices) can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g., crossing fiber tracts. Recently, a number of high-angular resolution schemes with more than six gradient directions have been employed to address this issue. In this article, we introduce the tensor distribution function (TDF), a probability function defined on the space of symmetric positive definite matrices. Using the calculus of variations, we solve the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function. Moreover, a tensor orientation distribution function (TOD) may also be derived from the TDF, allowing for the estimation of principal fiber directions and their corresponding eigenvalues. |
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Authors:
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A D Leow; S Zhu; L Zhan; K McMahon; G I de Zubicaray; M Meredith; M J Wright; A W Toga; P M Thompson |
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Publication Detail:
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Type: Evaluation Studies; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine Volume: 61 ISSN: 1522-2594 ISO Abbreviation: Magn Reson Med Publication Date: 2009 Jan |
Date Detail:
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Created Date: 2008-12-24 Completed Date: 2009-02-27 Revised Date: 2011-09-26 |
Medline Journal Info:
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Nlm Unique ID: 8505245 Medline TA: Magn Reson Med Country: United States |
Other Details:
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Languages: eng Pagination: 205-14 Citation Subset: IM |
Affiliation:
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Neuropsychiatric Hospital and LONI (Laboratory of NeuroImaging), University of California, Los Angeles, California 90095, USA. feuillet@ucla.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Algorithms* Brain / anatomy & histology* Computer Simulation Data Interpretation, Statistical Diffusion Magnetic Resonance Imaging / methods* Humans Image Enhancement / methods* Image Interpretation, Computer-Assisted / methods* Imaging, Three-Dimensional / methods* Models, Neurological Models, Statistical Nerve Fibers, Myelinated / ultrastructure* Reproducibility of Results Sensitivity and Specificity Statistical Distributions |
| Grant Support | |
ID/Acronym/Agency:
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R01 EB007813/EB/NIBIB NIH HHS; R01 EB007813-02/EB/NIBIB NIH HHS; R01 EB008281/EB/NIBIB NIH HHS; R01 EB008281-12/EB/NIBIB NIH HHS; R01 HD050735/HD/NICHD NIH HHS; R01 HD050735-02/HD/NICHD NIH HHS; R01 HD050735-05/HD/NICHD NIH HHS; U54 RR021813-05/RR/NCRR NIH HHS; U54 RR02183/RR/NCRR NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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