Fmriprep test data with fieldmap

I would like to use fmriprep for preprocessing fmri data with distortion correction. I have been having problems finding a publicly available data set that contains phase difference field maps and/or blip-up/blip-down calibration scans. I have browsed the public data sets hosted on This leads me to two questions.

  1. Does anyone know where I can find such a data set? I have tried to run fmriprep on my own data set with fieldmap correction without much success. I am hoping to run it on fmriprep on a known test data set to have a better understanding of where my data set is failing.

  2. Since I have found lots of data sets acquired without distortion correction (or at least posted without it) does this imply that people feel that acquiring and applying distortion correction is just not worth the trouble.


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This type of fieldmaps is still surprisingly uncommon. However, I have BIDSified an example HCP participant that you can use as a template:

As for your second question - this is a topic of a heated debate. Opinions range from: you need to acquire fieldmaps with all BOLD images to it does not really matter in context of spatial resolution of most sequences and smoothing applied to them.