Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.

Single-shot echo-planar imaging has been used widely in diffusion magnetic resonance imaging due to the difficulties in correcting motion-induced phase corruption in multishot data. Readout-segmented EPI has addressed the multishot problem by introducing a two-dimensional nonlinear navigator correct...

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Main Authors: Frost, R, Porter, D, Miller, K, Jezzard, P
Format: Journal article
Language:English
Published: 2012
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author Frost, R
Porter, D
Miller, K
Jezzard, P
author_facet Frost, R
Porter, D
Miller, K
Jezzard, P
author_sort Frost, R
collection OXFORD
description Single-shot echo-planar imaging has been used widely in diffusion magnetic resonance imaging due to the difficulties in correcting motion-induced phase corruption in multishot data. Readout-segmented EPI has addressed the multishot problem by introducing a two-dimensional nonlinear navigator correction with online reacquisition of uncorrectable data to enable acquisition of high-resolution diffusion data with reduced susceptibility artifact and T*(2) blurring. The primary shortcoming of readout-segmented EPI in its current form is its long acquisition time (longer than similar resolution single-shot echo-planar imaging protocols by approximately the number of readout segments), which limits the number of diffusion directions. By omitting readout segments at one side of k-space and using partial Fourier reconstruction, readout-segmented EPI imaging times could be reduced. In this study, the effects of homodyne and projection onto convex sets reconstructions on estimates of the fractional anisotropy, mean diffusivity, and diffusion orientation in fiber tracts and raw T(2)- and trace-weighted signal are compared, along with signal-to-noise ratio results. It is found that projections onto convex sets reconstruction with 3/5 segments in a 2 mm isotropic diffusion tensor image acquisition and 9/13 segments in a 0.9 × 0.9 × 4.0 mm(3) diffusion-weighted image acquisition provide good fidelity relative to the full k-space parameters. This allows application of readout-segmented EPI to tractography studies, and clinical stroke and oncology protocols.
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spelling oxford-uuid:6fdaec02-cff4-4e4a-b71d-efae842672782022-03-26T19:33:19ZImplementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:6fdaec02-cff4-4e4a-b71d-efae84267278EnglishSymplectic Elements at Oxford2012Frost, RPorter, DMiller, KJezzard, PSingle-shot echo-planar imaging has been used widely in diffusion magnetic resonance imaging due to the difficulties in correcting motion-induced phase corruption in multishot data. Readout-segmented EPI has addressed the multishot problem by introducing a two-dimensional nonlinear navigator correction with online reacquisition of uncorrectable data to enable acquisition of high-resolution diffusion data with reduced susceptibility artifact and T*(2) blurring. The primary shortcoming of readout-segmented EPI in its current form is its long acquisition time (longer than similar resolution single-shot echo-planar imaging protocols by approximately the number of readout segments), which limits the number of diffusion directions. By omitting readout segments at one side of k-space and using partial Fourier reconstruction, readout-segmented EPI imaging times could be reduced. In this study, the effects of homodyne and projection onto convex sets reconstructions on estimates of the fractional anisotropy, mean diffusivity, and diffusion orientation in fiber tracts and raw T(2)- and trace-weighted signal are compared, along with signal-to-noise ratio results. It is found that projections onto convex sets reconstruction with 3/5 segments in a 2 mm isotropic diffusion tensor image acquisition and 9/13 segments in a 0.9 × 0.9 × 4.0 mm(3) diffusion-weighted image acquisition provide good fidelity relative to the full k-space parameters. This allows application of readout-segmented EPI to tractography studies, and clinical stroke and oncology protocols.
spellingShingle Frost, R
Porter, D
Miller, K
Jezzard, P
Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title_full Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title_fullStr Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title_full_unstemmed Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title_short Implementation and assessment of diffusion-weighted partial Fourier readout-segmented echo-planar imaging.
title_sort implementation and assessment of diffusion weighted partial fourier readout segmented echo planar imaging
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AT porterd implementationandassessmentofdiffusionweightedpartialfourierreadoutsegmentedechoplanarimaging
AT millerk implementationandassessmentofdiffusionweightedpartialfourierreadoutsegmentedechoplanarimaging
AT jezzardp implementationandassessmentofdiffusionweightedpartialfourierreadoutsegmentedechoplanarimaging