Different sdc results for fmriprep versions 21.0.2 and 23.0.2

[jsein]

Hi,

This adds to the usual suspect cases of SDC with the phase difference method.

Similar issues were reported here:

Making Sure that the SDC has well-Applied

@jsein Thank you so much again for your time and the detailed guidance. I have applied SDC using fMRIPrep LTS v20.2.7 as suggested, the output looks pretty reasonable. [SDC_LTSv20.2.7] I checked the fieldmap less SDC by including --use-syn-sdc flag with both v23.0.1 and v20.2.7_LTS. It did work fine to some extent for v.20.2.7 but not good for v23.0.1. The outputs are as follows: synsdc with LTS v20.2.7 [synsdc_LTS20.2.7] synsdc with v23.0.1 [synsdc_v23.0.1] I started skullstripping t…

More distorted images using --use-syn-sdc on fmriprep 23.0.1 than fmriprep 22.0.2

Summary of what happened: Dear fMRIprep experts, I previously used the --use-syn-sdc for two sets of data using version 22.0.2 then re-ran the pre-processing after deleting all the output files using the latest version 23.0.1 and noticed that the images are more distorted compared to that using the older version (see attached screenshots below; subject 1 and 2 are from a different group than subject 3 and 4). Not sure if this is relevant but I previously did not include the --cifti-output fl…

Fieldmap correction gone wrong

Yes @jsein, it turns out changing only the fMRIPrep version to 20.2.7 led to WAY better distortion correction: In light of this, I’ll be interested to hear what developers think about next steps.