Scaling in Readout Direction: A Vibration-Induced Distortion of Diffusion-Weighted Images and Its Retrospective Correction by Affine Registration

Siawoosh Mohammadi¹, Michael Deppe¹, Harald E. Moller²

The strong lobes of the diffusion gradients cause different kinds of MR artifacts, like eddy-current (EC) and vibration effects. While EC effects could significantly be reduced using a twice-refocused spin-echo (TRSE) sequence for DTI acquisition, the vibration effects become more evident when the TRSE sequence is used. We showed that the vibration-induced motion leads to an affine scaling effect in x and y-direction that could be retrospectively corrected. While the y scaling is also subject to EC effects, the x scaling seems to correct solely vibration effects and might thus be usable for comparing vibration effects of different data sets.