Registration-based distortion correction

Hello everyone,
I have a DTI dataset for Parkinson’s disease (each subject has 64 gradient images and 1 b0 image) without any additional images(field map, phase image, etc.). I want to use a way for distortion correction of my dataset and I can’t use Topup or Eddy Current or other ways needed additional information. I saw a registration-based distortion correction method that didn’t need any additional data but I don’t know how to implement this method with FSL.
I would be grateful to hear from you as soon as possible.

Have you tried Tortoise? They have a registration based correction called DIFF PREP.

https://tortoise.nibib.nih.gov/

I must try it…Thank you

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