Diffusion tensor image corregistration

Operating system: Ubuntu
Slicer version: 3.6.3, 4.10.2
Expected behavior: How can I do the corregistration of corticospinal tract to mprage volumetric image?
Actual behavior: I am processing the corticospinal tract, but I need to do the corregistration to mprage volumetric image.

Often the structural and diffusion images will be in the same space. If not, when you convert DWI to DTI, you also get a baseline volume, which can be used for registration. If you only have a DTI, you could try different derived scalars for registration.