A method for processing MRI data in which a reference direction and a first voxel are selected. A first transverse orientation vector associated with the first voxel is determined. This first transverse orientation vector is normal to the reference direction. On the basis of the first transverse orientation vector, a second voxel is selected. A second transverse orientation vector associated with the second voxel is also selected. This second transverse orientation vector is likewise normal to the reference direction. The method also includes determining whether a relationship between the first and second transverse orientation vectors is consistent with a track normal to the reference direction and extending between the first and second voxels.