Fast structural brain imaging using an MDEFT sequence with a FLASH-EPI hybrid readout.
A sequence for the fast acquisition of T1 weighted structural brain images with whole brain coverage and isotropic resolution of 1mm is presented. It is based on MDEFT with a FLASH-EPI hybrid readout. Several techniques for artefact suppression are implemented, like echo time shifting, asymmetric k-space sampling, and navigator echo acquisition. It is shown experimentally that the hybrid MDEFT sequence with a total duration of 8min yields approximately the same signal-to-noise and contrast-to-noise ratios as a 12min standard MDEFT sequence based on a FLASH readout. Further experiments show that echo time shifting suppresses artefacts in the vicinity of the scalp and in areas suffering from field inhomogeneities and that the concept of asymmetric k-space sampling reduces the susceptibility to head movement.
Deichmann
R
R
Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, UK. r.deichmann@fil.ion.ucl.ac.uk
D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D017352:Echo-Planar Imaging / Q000379:methods; D005583:Fourier Analysis; D006801:Humans; D013997:Time Factors