A New Distortion Model for Strong Inhomogeneity Problems in Echo-Planar MRI

dc.creatorZibetti, MVW
dc.creatorDe Pierro, AR
dc.date2009
dc.dateNOV
dc.date2014-11-13T20:12:08Z
dc.date2015-11-26T17:11:24Z
dc.date2014-11-13T20:12:08Z
dc.date2015-11-26T17:11:24Z
dc.date.accessioned2018-03-28T23:59:54Z
dc.date.available2018-03-28T23:59:54Z
dc.identifierIeee Transactions On Medical Imaging. Ieee-inst Electrical Electronics Engineers Inc, v. 28, n. 11, n. 1736, n. 1753, 2009.
dc.identifier0278-0062
dc.identifierWOS:000271437600009
dc.identifier10.1109/TMI.2009.2022622
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/76169
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/76169
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/76169
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1281088
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionThis paper proposes a new distortion model for strong inhomogeneity problems in echo planar imaging (EPI). Fast imaging sequences in magnetic resonance imaging (MRI), such as EPI, are very important in applications where temporal resolution or short total acquisition time is essential. Unfortunately, fast imaging sequences are very sensitive to variations in the homogeneity of the main magnetic field. The inhomogeneity leads to geometrical distortions and intensity changes in the image reconstructed via fast Fourier transform. Also, under strong inhomogeneity, the accelerated intravoxel dephase may overly attenuate signals coming from regions with higher inhomogeneity variations. Moreover, coarse discretization schemes for the inhomogeneity are not able to cope with this problem, producing discretization artifacts when large inhomogeneity variations occur. Most of the existing models do not attempt to solve this problem. In this paper, we propose a modification of the discrete distortion model to incorporate the effects of the intravoxel inhomogeneity and to minimize the discretization artifacts. As a result, these problems are significantly reduced. Extensive experiments are shown to demonstrate the achieved improvements. Also, the performance of the new model is evaluated for conjugate phase, least squares method (minimized iteratively using conjugated gradients), and regularized methods (using a total variation penalty).
dc.description28
dc.description11
dc.description1736
dc.description1753
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionFAPESP [06/06797-4, 2002/07153-2]
dc.descriptionCNPq [476825/2006-0, 304820/2006-7]
dc.languageen
dc.publisherIeee-inst Electrical Electronics Engineers Inc
dc.publisherPiscataway
dc.publisherEUA
dc.relationIeee Transactions On Medical Imaging
dc.relationIEEE Trans. Med. Imaging
dc.rightsfechado
dc.rightshttp://www.ieee.org/publications_standards/publications/rights/rights_policies.html
dc.sourceWeb of Science
dc.subjectDiscretization
dc.subjectecho-planar imaging
dc.subjectmagnetic field inhomogeneity
dc.subjectmagnetic resonance imaging (MRI)
dc.subjectregularization
dc.subjecttotal variation
dc.subjectIterative Image-reconstruction
dc.subjectFast Fourier-transforms
dc.subjectEpi
dc.titleA New Distortion Model for Strong Inhomogeneity Problems in Echo-Planar MRI
dc.typeArtículos de revistas


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