fMRIprep phase data requirements for fieldmaps

[Luke_Vano]

Summary of what happened:

I am using fMRIprep to process my fMRI data and was hoping to use magnitude and phase data at different echo times of a GRE sequence for the distortion correction. I would like to check that I have uploaded the data in the correct format, as there are a few steps that are unclear to me and the resulting corrected BOLD images appear suboptimal.
My main questions are:

1. Have I used constructed the .json files correctly?
2. Is the phase data in the correct units?

I am using fMRIprep v23.2.1 and my data is BIDS compliant.

I get the following lines of code which I believe means that fMRIprep is correctly identifying my mag and phase images and will use them to generate the B0 field map:

240725-13:47:00,986 nipype.workflow INFO:
	 B0 field inhomogeneity map will be estimated with the following 1 estimator(s): [<EstimatorType.PHASEDIFF: 3>].
240725-13:47:01,42 nipype.workflow INFO:
	 Setting-up fieldmap "fmap0" (EstimatorType.PHASEDIFF) with <sub-031_magnitude1.nii.gz, sub-031_magnitude2.nii.gz, sub-031_phase1.nii.gz, sub-031_phase2.nii.gz>

Below shows the contents of the .json files. Do they look correct?

sub-031_magnitude1.json:

{
        "EchoTime": 0.00584,
        "IntendedFor": [
                "func/sub-031_task-rest_run-1_bold.nii"
        ],
        "B0FieldIdentifier": "fmap0"
}

sub-031_magnitude2.json:

{
        "EchoTime": 0.01063,
        "IntendedFor": [
                "func/sub-031_task-rest_run-1_bold.nii"
        ],
        "B0FieldIdentifier": "fmap0"
}

sub-031_phase1.json:

{
        "EchoTime": 0.00584,
        "IntendedFor": [
                "func/sub-031_task-rest_run-1_bold.nii"
        ],
        "B0FieldIdentifier": "fmap0"
}

sub-031_phase2.json:

{
        "EchoTime": 0.01063,
        "IntendedFor": [
                "func/sub-031_task-rest_run-1_bold.nii"
        ],
        "B0FieldIdentifier": "fmap0"
}

These phase maps are wrapped between 0 and 2 pi. The image below shows the data for _phase1.nii.gz. Is this correct?