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nipreps / sdcflows

Susceptibility Distortion Correction (SDC) workflows for EPI MR schemes
https://www.nipreps.org/sdcflows
Apache License 2.0
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inconsistent contrast in PEB/PEPOLAR #447

Open mitchellxh opened 5 months ago

mitchellxh commented 5 months ago

What happened?

I'm having trouble trying to identify what is happening during SDC. Using the same fmaps on different runs within the same session, when reviewing the distorted/corrected gifs, the contrast is enhanced in both panels for some runs and the contrast is not enhanced in the corrected panels for others. Including an example of run-2 (inconsistent) and run-6 (consistent) as an example of what I'm referring to.

vary constant

I can't exactly explain why this behavior is happening? It seems almost that for some runs the collage of the corrected SDC is using the same enhanced boldref and in others it's using a boldref that not enhanced?

When I look at the contrasts for the input bold and output bolds, there both consistently matching the low-contrasts, so I'm not sure if this has any actual affect on the output?

What command did you use?

fmriprep $bids_dir $bids_dir/derivatives --skip-bids-validation participant -w $working_dir/work.2023.06.12 --participant-label $subjid --mem_mb 20000 --nthreads 8 --output-spaces fsaverage MNI152NLin2009cAsym T1w -t vis

What version of the software are you running?

22.0.2

How are you running this software?

Singularity

Is your data BIDS valid?

No

Are you reusing any previously computed results?

No

Please copy and paste any relevant log output.

No response

Additional information / screenshots

No response

effigies commented 1 month ago

Sorry, this got lost in the summer conference season. Are you still seeing this with the latest fmriprep?