title: Pushing spatial and temporal resolution for functional and diffusion MRI in the Human Connectome Project.
abstract: The Human Connectome Project (HCP) relies primarily on three complementary magnetic resonance (MR) methods. These are: 1) resting state functional MR imaging (rfMRI) which uses correlations in the temporal fluctuations in an fMRI time series to deduce 'functional connectivity'; 2) diffusion imaging (dMRI), which provides the input for tractography algorithms used for the reconstruction of the complex axonal fiber architecture; and 3) task based fMRI (tfMRI), which is employed to identify functional parcellation in the human brain in order to assist analyses of data obtained with the first two methods. We describe technical improvements and optimization of these methods as well as instrumental choices that impact speed of acquisition of fMRI and dMRI images at 3T, leading to whole brain coverage with 2 mm isotropic resolution in 0.7 s for fMRI, and 1.25 mm isotropic resolution dMRI data for tractography analysis with three-fold reduction in total dMRI data acquisition time. Ongoing technical developments and optimization for acquisition of similar data at 7 T magnetic field are also presented, targeting higher spatial resolution, enhanced specificity of functional imaging signals, mitigation of the inhomogeneous radio frequency (RF) fields, and reduced power deposition. Results demonstrate that overall, these approaches represent a significant advance in MR imaging of the human brain to investigate brain function and structure.
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA. kamil@cmrr.umn.edu
authors.forename: Kamil
authors.initials: K
authors.lastname: Uğurbil
authors.forename: Junqian
authors.initials: J
authors.lastname: Xu
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Auerbach
authors.forename: Steen
authors.initials: S
authors.lastname: Moeller
authors.forename: An T
authors.initials: AT
authors.lastname: Vu
authors.forename: Julio M
authors.initials: JM
authors.lastname: Duarte-Carvajalino
authors.forename: Christophe
authors.initials: C
authors.lastname: Lenglet
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wu
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmitter
authors.forename: Pierre Francois
authors.initials: PF
authors.lastname: Van de Moortele
authors.forename: John
authors.initials: J
authors.lastname: Strupp
authors.forename: Guillermo
authors.initials: G
authors.lastname: Sapiro
authors.forename: Federico
authors.initials: F
authors.lastname: De Martino
authors.forename: Dingxin
authors.initials: D
authors.lastname: Wang
authors.forename: Noam
authors.initials: N
authors.lastname: Harel
authors.forename: Michael
authors.initials: M
authors.lastname: Garwood
authors.forename: Liyong
authors.initials: L
authors.lastname: Chen
authors.forename: David A
authors.initials: DA
authors.lastname: Feinberg
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Smith
authors.forename: Karla L
authors.initials: KL
authors.lastname: Miller
authors.forename: Stamatios N
authors.initials: SN
authors.lastname: Sotiropoulos
authors.forename: Saad
authors.initials: S
authors.lastname: Jbabdi
authors.forename: Jesper L R
authors.initials: JL
authors.lastname: Andersson
authors.forename: Timothy E J
authors.initials: TE
authors.lastname: Behrens
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Glasser
authors.forename: David C
authors.initials: DC
authors.lastname: Van Essen
authors.forename: Essa
authors.initials: E
authors.lastname: Yacoub
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D063132:Connectome / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008953:Models, Anatomic; D008959:Models, Neurological; D009415:Nerve Net / Q000033:anatomy & histology* / Q000502:physiology*; D062211:Spatio-Temporal Analysis