Identifying field-mapping resources

Base fieldmap estimation

• Subject can have phase-difference data.
• Subject can have a fieldmap acquisition.

fmriprep.workflows.fieldmap.base.init_fmap_estimator_wf(fmap_bids, reportlets_dir, omp_nthreads, fmap_bspline)

This workflow selects the fieldmap estimation data available for the subject and returns the estimated fieldmap in mm, along with a corresponding reference image. Current implementation applies the first type of fieldmap estimation found in the following order of precedence:

• “Natural” fieldmaps
• Phase-difference fieldmaps

Outputs:

fmap

The estimated fieldmap itself IN UNITS OF Hz.

fmap_ref

the anatomical reference for the fieldmap (magnitude image, corrected SEm, etc.)

fmap_mask

a brain mask for the fieldmap