Open AccessTurbo-FLASH Based Arterial Spin Labeled Perfusion MRI at 7 T
Author(s) -
Zhentao Zuo,
Rui Wang,
Yan Zhuo,
Rong Xue,
Keith St. Lawrence,
Danny J.J. Wang
Publication year - 2013
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0066612
Subject(s) - perfusion scanning , precentral gyrus , primary motor cortex , perfusion , turbo , image resolution , physics , specific absorption rate , nuclear magnetic resonance , temporal resolution , computer science , magnetic resonance imaging , motor cortex , neuroscience , medicine , optics , biology , cardiology , radiology , telecommunications , stimulation , automotive engineering , antenna (radio) , engineering
Motivations of arterial spin labeling (ASL) at ultrahigh magnetic fields include prolonged blood T 1 and greater signal-to-noise ratio (SNR). However, increased B 0 and B 1 inhomogeneities and increased specific absorption ratio (SAR) challenge practical ASL implementations. In this study, Turbo-FLASH (Fast Low Angle Shot) based pulsed and pseudo-continuous ASL sequences were performed at 7T, by taking advantage of the relatively low SAR and short TE of Turbo-FLASH that minimizes susceptibility artifacts. Consistent with theoretical predictions, the experimental data showed that Turbo-FLASH based ASL yielded approximately 4 times SNR gain at 7T compared to 3T. High quality perfusion images were obtained with an in-plane spatial resolution of 0.85×1.7 mm 2 . A further functional MRI study of motor cortex activation precisely located the primary motor cortex to the precentral gyrus, with the same high spatial resolution. Finally, functional connectivity between left and right motor cortices as well as supplemental motor area were demonstrated using resting state perfusion images. Turbo-FLASH based ASL is a promising approach for perfusion imaging at 7T, which could provide novel approaches to high spatiotemporal resolution fMRI and to investigate the functional connectivity of brain networks at ultrahigh field.