Symmetric diffeomorphic registration of fibre orientation distributions

► A new method for registration of fibre orientation distributions (FOD) is presented. ► Quantitative validation is performed using two FOD image metrics on human brain data. ► The cross-correlation metric outperforms the mean squared difference metric. ► Higher-order information in FODs improves white matter alignment. ► The method is applied to a potential application: group average FOD tractography.