Two-axis acceleration of functional connectivity magnetic resonance imaging by parallel excitation of phase-tagged slices and half k-space acceleration. Brain Connect 2011;1(1):81-90
Date
01/01/2011Pubmed ID
22432957Pubmed Central ID
PMC3312804DOI
10.1089/brain.2011.0004Scopus ID
2-s2.0-85006186246 (requires institutional sign-in at Scopus site) 13 CitationsAbstract
Whole brain functional connectivity magnetic resonance imaging requires acquisition of a time course of gradient-recalled (GR) volumetric images. A method is developed to accelerate this acquisition using GR echo-planar imaging and radio frequency (RF) slice phase tagging. For N-fold acceleration, a tailored RF pulse excites N slices using a uniform-field transmit coil. This pulse is the Fourier transform of the profile for the N slices with a predetermined RF phase tag on each slice. A multichannel RF receive coil is used for detection. For n slices, there are n/N groups of slices. Signal-averaged reference images are created for each slice within each slice group for each member of the coil array and used to separate overlapping images that are simultaneously received. The time-overhead for collection of reference images is small relative to the acquisition time of a complete volumetric time course. A least-squares singular value decomposition method allows image separation on a pixel-by-pixel basis. Twofold slice acceleration is demonstrated using an eight-channel RF receive coil, with application to resting-state functional magnetic resonance imaging in the human brain. Data from six subjects at 3 T are reported. The method has been extended to half k-space acquisition, which not only provides additional acceleration, but also facilitates slice separation because of increased signal intensity of the central lines of k-space coupled with reduced susceptibility effects.
Author List
Jesmanowicz A, Nencka AS, Li SJ, Hyde JSAuthor
Andrew S. Nencka PhD Director, Associate Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
BrainBrain Mapping
Echo-Planar Imaging
Humans
Magnetic Resonance Imaging
Nerve Net
