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Navigated diffusion-weighted imaging with interpolated phase-correction for high-resolution imaging of stroke.

J Bernarding·E Gedat·H C Koennecke·J Braun
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Abstract

Stroke imaging was revolutionised with the introduction of diffusion-weighted MRI (DWI). The commonly used echoplanar DWI suffers from geometrical distortion near the skull base and the frontal regions and from reduced spatial resolution and fat suppression. To allow a voxel-by-voxel comparison between high-resolution spin-echo images, we implemented spin-echo-based DWI. Motion artefacts were eliminated by phase correction in hybrid frequency-Fourier domain using navigator echoes. In a novel approach, distorted navigator echoes which did not eliminate motion artefacts were replaced with interpolated navigator echoes, leading to restored image information. Navigated DWI yielded high-resolution images in 21 of 24 patients with brain ischaemia, allowing diagnosis of even small or diffuse zones of ischaemia. We determined the spatial distribution and mean of T(2)- and DWI signal intensity and apparent diffusion coefficients (ADC), using a multidimensional histogram-based analysis. Mean ADC were decreased in ischaemic areas less than 9 days old. The technique may also be useful for high-resolution DWI of tissue other than the brain.

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AgedArtifactsBrainDiffusion Magnetic Resonance ImagingFemaleHumansImage Processing, Computer-AssistedMaleMiddle AgedStrokeJournal ArticleResearch Support, Non-U.S. Gov't

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J Bernarding, E Gedat, H C Koennecke, J Braun. 2003-10-08. Navigated diffusion-weighted imaging with interpolated phase-correction for high-resolution imaging of stroke.. https://doi.org/10.1007/s00234-003-1063-4

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