mne_bids.get_head_mri_trans

mne_bids.get_head_mri_trans(bids_path, extra_params=None, t1_bids_path=None, fs_subject=None, fs_subjects_dir=None)[source]

Produce transformation matrix from MEG and MRI landmark points.

Will attempt to read the landmarks of Nasion, LPA, and RPA from the sidecar files of (i) the MEG and (ii) the T1-weighted MRI data. The two sets of points will then be used to calculate a transformation matrix from head coordinates to MRI coordinates.

Note

The MEG and MRI data need not necessarily be stored in the same session or even in the same BIDS dataset. See the t1_bids_path parameter for details.

Parameters
bids_pathmne_bids.BIDSPath

The path of the electrophysiology recording.

extra_paramsNone | dict

Extra parameters to be passed to mne.io.read_raw() when reading the MEG file.

t1_bids_pathmne_bids.BIDSPath | None

If None (default), will try to discover the T1-weighted MRI file based on the name and location of the MEG recording specified via the bids_path parameter. Alternatively, you explicitly specify which T1-weighted MRI scan to use for extraction of MRI landmarks. To do that, pass a mne_bids.BIDSPath pointing to the scan. Use this parameter e.g. if the T1 scan was recorded during a different session than the MEG. It is even possible to point to a T1 image stored in an entirely different BIDS dataset than the MEG data.

fs_subjectstr | None

The subject identifier used for FreeSurfer. If None, defaults to the subject entity in bids_path.

fs_subjects_dirstr | pathlib.Path | None

The FreeSurfer subjects directory. If None, defaults to the SUBJECTS_DIR environment variable.

New in version 0.8.

Returns
transmne.transforms.Transform

The data transformation matrix from head to MRI coordinates.