Navigation(children) Index TableOfContents

Name

mris_ca_train - Creates a cortical parcellation atlas file based on one or more annotated subjects. mris_ca_train builds probabilistic information estimated from a manually labeled training set (of annotated subjects). Note that an "annotation" is synonymous with a "parcellation", and is used for backwards compatibility. The manual labeling can be carried out directly on surface models using drawing tools in tksurfer, or volumetrically, then sampled onto the surfaces using ["mris_sample_parc"]. This information is then used by ["mris_ca_label"] to automatically assign a neuroanatomical label to each location on a cortical surface model. This procedure incorporates both geometric information derived from the cortical model (sulcus and curvature), and neuroanatomical convention, as found in the training set. The result of mris_ca_train and mris_ca_label is a complete labeling of cortical sulci and gyri.

Synopsis

mris_ca_train [options] <hemi> <canonsurf> <annotfile> <subject1> [subject2 ...] <outputfile>

Arguments

Positional Arguments

Required Positional Arguments

hemi canonsurf annotfile subject1 outputfile

Optional Flagged Arguments

Outputs

Example

mris_ca_train -n 2 \
    -t ./my_color_file.txt \
    lh \
    sphere.reg \
    my_manual_labeling \
    $SUBJECTS \
    ./lh.my_atlas.gcs

In this example, mris_ca_train would look for an annotation file named lh.my_manual_labeling.annot in each of the subjects listed in $SUBJECTS label dir (e.g. $SUBJECTS_DIR/$s/label), and also assumes that a canonical surface file named lh.sphere.reg exists in the surf dir of each subject.

An annotation file is created in tksurfer. See wiki pages ["tksurfer_labeledit"] or [wiki:TkSurferGuide/TkSurferWorkingWithData/TkSurferLabel TkSurferLabel]. File->Label->Export Annotation is what exports all labels that have been assigned to a structure into the .annot file. To make assignments, open the 'Labels' window, via View->Windows->Labels, and assign each label to a structure and it's associated color. If you want to modify the set of available structures (and their colors), then you should create a new file in the same format as $FREESURFER_HOME/FreeSurferColorLUT.txt and select File->Lable->Load Color Table.

The -n 2 option tells it to use two feature dimensions for classification: curv and sulc (which is what is used by default).

The -t ./my_color_file.txt option will read in the file my_color_file.txt and embed it in the atlas, so that mris_ca_label will put it in the automatically generated .annot files, so that later, tksurfer (and other things) can read it in.

The format of the my_color_file.txt file consists of a set of lines like:

1   Corpus_callosum     50      50      50      0

where the last value (0, in this example) is not used, and the 50s are r,g,b (red,green,blue) values. They must match what is in the annot file, in which each vertex is given the value: r+(g << 8)+(b << 16).

Bugs

None

See Also

["mris_sample_parc"], ["mris_ca_label"], SurfaceRegAndTemplates

Links

CorticalParcellation, FreeSurfer, FsFast

References

[https://surfer.nmr.mgh.harvard.edu/ftp/articles/fischl04-parcellation.pdf Automatically Parcellating the Human Cerebral Cortex], Fischl et al., (2004). Cerebral Cortex, 14:11-22.

Reporting Bugs

Report bugs to <analysis-bugs@nmr.mgh.harvard.edu>

Author/s

BruceFischl