Dcm2bids config file fmap labelling issue


I have two distortion maps that are epi images in the opposite direction of our MRI scans. When dcm2bids runs, it assumes that the first field map is run 1 and the second is run 2. Is there any way to change the labeling so that the labeling of the file indicates the task type it is intended for or would this not be bids compliant? Here is what I am getting…


I want…


Here is what I have included in the config map for these items. Custom labeling doesn’t appear to be working.

Fieldmap for the resting state scan…
“dataType”: “fmap”,
“modalityLabel”: “epi”,
“customLabels”: “dir-AP-cyb”,
“intendedFor”: [
“criteria”: {
“SeriesDescription”: “Cyberball_dir-PA”,
“ProtocolName”: “distmap”,
“PhaseEncodingDirection”: “j”

"dataType": "fmap",
  "modalityLabel": "epi",
  "customLabels": "dir-AP-rest",
  "intendedFor": [
  "criteria": {
    "SeriesDescription": "*REST*",
    "ProtocolName": "*distmap*",
    "PhaseEncodingDirection": "j"

Hi @AustinBipolar,

These names aren’t BIDS-compliant and will generate an error if you try to validate your dataset through the BIDS validator. I would instead recommend using the acq entity label to differentiate which BOLD images these field maps are meant to be applied to. I’m unsure if you meant to specify that these are two separate subjects, but assuming so, something like this would be BIDS-compliant:


It’s been awhile since I’ve used dcm2bids and its configuration file, but I think the only thing you’d need to change would be the "customLabels" fields to:

"customLabels": "acq-rest_dir-AP", 
"customLabels": "acq-cyb_dir-AP",

Hope this helps.

Awesome, that works great. Thank you so much!