title: High-resolution diffusion MRI at 7T using a three-dimensional multi-slab acquisition.
abstract: High-resolution diffusion MRI can provide the ability to resolve small brain structures, enabling investigations of detailed white matter architecture. A major challenge for in vivo high-resolution diffusion MRI is the low signal-to-noise ratio. In this work, we combine two highly compatible methods, ultra-high field and three-dimensional multi-slab acquisition to improve the SNR of high-resolution diffusion MRI. As each kzplane is encoded using a single-shot echo planar readout, scan speeds of the proposed technique are similar to the commonly used two-dimensional diffusion MRI. In-plane parallel acceleration is applied to reduce image distortions. To reduce the sensitivity of auto-calibration signal data to subject motion and respiration, several new adaptions of the fast low angle excitation echo-planar technique (FLEET) that are suitable for 3D multi-slab echo planar imaging are proposed and evaluated. A modified reconstruction scheme is proposed for auto-calibration with the most robust method, Slice-FLEET acquisition, to make it compatible with navigator correction of motion induced phase errors. Slab boundary artefacts are corrected using the nonlinear slab profile encoding method recently proposed by our group. In vivo results demonstrate that using 7T and three-dimensional multi-slab acquisition with improved auto-calibration signal acquisition and nonlinear slab boundary artefacts correction, high-quality diffusion MRI data with ~1mm isotropic resolution can be achieved.
authors: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK. Electronic address: wenchuan.wu@ndcn.ox.ac.uk.
authors: Wenchuan
authors: W
authors: Wu
authors: Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200MD Maastricht, The Netherlands.
authors: Benedikt A
authors: BA
authors: Poser
authors: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors: Gwenaëlle
authors: G
authors: Douaud
authors: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors: Robert
authors: R
authors: Frost
authors: Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA.
authors: Myung-Ho
authors: MH
authors: In
authors: Department of Biomedical Magnetic Resonance, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany; Leibniz Institute for Neurobiology, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; German Center for Neurodegenerative Disease, Site Magdeburg, Germany.
authors: Oliver
authors: O
authors: Speck
authors: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors: Peter J
authors: PJ
authors: Koopmans
authors: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors: Karla L
authors: KL
authors: Miller
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*
keywords: 3D; 7T; Diffusion; High resolution; Multi-slab; Tractography