Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-5-2
pubmed:abstractText
High angular resolution diffusion imaging (HARDI) has become an important technique for imaging complex oriented structures in the brain and other anatomical tissues. This has motivated the recent development of several methods for computing the orientation probability density function (PDF) at each voxel. However, much less work has been done on developing techniques for filtering, interpolation, averaging and principal geodesic analysis of orientation PDF fields. In this paper, we present a Riemannian framework for performing such operations. The proposed framework does not require that the orientation PDFs be represented by any fixed parameterization, such as a mixture of von Mises-Fisher distributions or a spherical harmonic expansion. Instead, we use a nonparametric representation of the orientation PDF. We exploit the fact that under the square-root re-parameterization, the space of orientation PDFs forms a Riemannian manifold: the positive orthant of the unit Hilbert sphere. We show that various orientation PDF processing operations, such as filtering, interpolation, averaging and principal geodesic analysis, may be posed as optimization problems on the Hilbert sphere, and can be solved using Riemannian gradient descent. We illustrate these concepts with numerous experiments on synthetic, phantom and real datasets. We show their application to studying left/right brain asymmetries.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1095-9572
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1181-201
pubmed:dateRevised
2011-8-1
pubmed:meshHeading
pubmed-meshheading:21292013-Algorithms, pubmed-meshheading:21292013-Animals, pubmed-meshheading:21292013-Anisotropy, pubmed-meshheading:21292013-Brain, pubmed-meshheading:21292013-Data Interpretation, Statistical, pubmed-meshheading:21292013-Diffusion Magnetic Resonance Imaging, pubmed-meshheading:21292013-Functional Laterality, pubmed-meshheading:21292013-Humans, pubmed-meshheading:21292013-Image Enhancement, pubmed-meshheading:21292013-Image Processing, Computer-Assisted, pubmed-meshheading:21292013-Linear Models, pubmed-meshheading:21292013-Models, Statistical, pubmed-meshheading:21292013-Nerve Fibers, pubmed-meshheading:21292013-Phantoms, Imaging, pubmed-meshheading:21292013-Population, pubmed-meshheading:21292013-Principal Component Analysis, pubmed-meshheading:21292013-Rats, pubmed-meshheading:21292013-Rats, Sprague-Dawley
pubmed:year
2011
pubmed:articleTitle
A nonparametric Riemannian framework for processing high angular resolution diffusion images and its applications to ODF-based morphometry.
pubmed:affiliation
Department of Mathematics, National University of Singapore, Singapore. agoh@nus.edu.sg
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural