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

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

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.