Hi, 2086--
So, fat_proc_convert_dcm_dwis is for converting DICOM files to NIFTI. To do the processing step of correcting EPI distortions (along with motion correction and eddy currents), we recommend using the TORTOISE tool, which is also freely available from the NIH:
[
science.nichd.nih.gov]
Their preference is typically to have fully matched AP and PA acquisitions, but I believe you can run TORTOISE just using a single phase encode in one set. I will PM you the email addresses of the TORTOISE folks to query about the specifics.
--pt