title: Tradeoffs in pushing the spatial resolution of fMRI for the 7T Human Connectome Project.
abstract: Whole-brain functional magnetic resonance imaging (fMRI), in conjunction with multiband acceleration, has played an important role in mapping the functional connectivity throughout the entire brain with both high temporal and spatial resolution. Ultrahigh magnetic field strengths (7T and above) allow functional imaging with even higher functional contrast-to-noise ratios for improved spatial resolution and specificity compared to traditional field strengths (1.5T and 3T). High-resolution 7T fMRI, however, has primarily been constrained to smaller brain regions given the amount of time it takes to acquire the number of slices necessary for high resolution whole brain imaging. Here we evaluate a range of whole-brain high-resolution resting state fMRI protocols (0.9, 1.25, 1.5, 1.6 and 2mm isotropic voxels) at 7T, obtained with both in-plane and slice acceleration parallel imaging techniques to maintain the temporal resolution and brain coverage typically acquired at 3T. Using the processing pipeline developed by the Human Connectome Project, we demonstrate that high resolution images acquired at 7T provide increased functional contrast to noise ratios with significantly less partial volume effects and more distinct spatial features, potentially allowing for robust individual subject parcellations and descriptions of fine-scaled patterns, such as visuotopic organization.
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA; Helen Wills Institute for Neuroscience, University of California, Berkeley, CA, USA; Advanced MRI Technologies, Sebastopol, CA, USA. Electronic address: an.vu2@va.gov.
authors.forename: An
authors.initials: A
authors.lastname: T Vu
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Jamison
authors.affiliation: Washington University School of Medicine, Washington University, St. Louis, MO, USA.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Glasser
authors.affiliation: FMRIB (Oxford Centre for Functional MRI of the Brain), Oxford University, Oxford, UK.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Smith
authors.affiliation: Washington University School of Medicine, Washington University, St. Louis, MO, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Coalson
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Steen
authors.initials: S
authors.lastname: Moeller
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Auerbach
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Kamil
authors.initials: K
authors.lastname: Uğurbil
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Essa
authors.initials: E
authors.lastname: Yacoub
mesh_terms: D063132:Connectome / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*
keywords: 7T; Connectome; High-resolution; Resting state; Whole brain; fMRI