The effect of local perturbation fields on human DTI: Characterisation, measurement and correction

► Measurement of local perturbation fields (LPFs) on three different scanners. ► LPFs are, e.g., diffusion-gradient non-linearities/mis-calibration. ► LPFs bias fractional anisotropy (FA) and mean diffusivity (MD) maps. ► Correction improves accuracy, FA contrast and comparability between scanners. ► Relevant for group, longitudinal or multi-centre studies.