Fetal SHARD DWI output files

1

Hi all!

I’m working with the pre-processed fetal data. In the dwi/ file for each subject in fmriresults01/dhcp_dmri_shard_pipeline, there are two niftis labeled preproc - sub-XXX_ses-XXXX_desc-preproc_**fe**_dwi.nii.gz and sub-XXX_ses-XXXX_desc-preproc_**se**_dwi.nii.gz.

Could anyone explain the difference between these two? There doesn’t seem to be any distinction in this documentation, or on the SHARD Github repo.

Thanks!

2

Hi, I have the exact same question - did you figure it out?

Best,
Gabriela

3

Hi all,

Slava Karolis at KCL kindly explained the difference between the files, so I am copying the response here in case it is useful to anyone else:

“The difference is that the acquisition was a mixture of Spin-Echo (se_dwi) and Field-Echo (fe_dwi), combining which allows estimation of the phase offset and hence distortion correction via phase unwrapping.”,

For tractography the “preprocessed_se_dwi” should be used as it has better image quality and reduced artefacts.

Best,
Gabriela