MRI_CT image registration

Hi all
I’m trying to register CT images with [512,512,48] and diffusion MRI with [128,128,68] dimensions. I am using general registration (BRAINS) modules with the following parameters:

fixed image: CT
Moving image: MRI
percentage of sample: 0.02
linear transform
rigid with 6 DOF

but the registration process encountered some fundamental simple ITK issues and the process did not finish.

I upload all data here:

I would be appreciated for your helps in advance.