Meeting Banner
Abstract #1898

Correction of Vibration Artefacts in DTI Using Phase-Encoding Reversal (COVIPER)

MAGNA25Siawoosh Mohammadi1, Zoltan Nagy1, Chloe Hutton1, Oliver Josephs1, Nikolaus Weiskopf1

1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom

Vibrations induced by strong diffusion gradients in DTI, cause an echo shift in k-space and consequential signal-loss. Here we present a simple method to correct these vibration artefacts using phase-encoding reversal (COVIPER) by combining two images with reversed PE direction, each weighted by a function of its local tensor fit error. COVIPER was validated against low vibration reference data, resulting in an error reduction of about 72% in FA maps. When COVIPER is combined with other corrections based on phase encoding reversal, they provide a comprehensive correction for eddy currents, susceptibility-related distortions and vibration artefacts in DTI.

Keywords

acquiring acquisition acquisitions affected affects apparent appropriate arithmetic arrows assess assessed asymmetric attributed background bias black blip brain capture clinical coefficients college combination combined comprehensive concept consequential containing contrast contribution correct correction corrections coverage dataset datasets denoted details developed diagrams differing diffusion distortions distributed eddy edge encoding error established extent female function furthermore goal gradient gradients healthy increasing individuals induce induced institute isotropic kingdom lead least local locally location longer loss made maps matrix measured middle misc miscellaneous models moreover motion movement negligible neurology note oliver opposite orange original partial patient planar posse previous proposed providing quantification quantified reconstruction recovered reduced reducing reduction refining related repetition residual resolution retrospectively reversal reversed reversing root rotational scanned scanner schematic sets short simple space spatial spherically square step still strong subject subjects subsequently substantial suffers supported susceptibility table tensor though tissue trio trust turn union usually validated varied vibration vibrations volunteers widely window zero