Index

Software version described:

• $Date: 2007/11/16 20:32:50 $
• $Revision: 1.15 $
• Use usage or version option to see version you are using

Name

mri_annotation2label - Inputs an annotation file and produces corresponding label files.

Synopsis

mri_annotation2label [Flagged arguments]

Arguments

Required Flagged Arguments

Optional Arguments

Description

The main purpose of this program is to convert an annotation file into multiple label files or into a segmentation 'volume'. It can also create a border overlay. Optionally it can create output files that contain label information in other forms. (This program cannot export the annotation file's LUT to text format -- if you need to do that, for example to verify it, you could use mris_anatomical_stats.

Inputs are specified via subject, hemisphere, and optionally, if the defaults are not wanted, a base name for the annotation, and a specific surface to be used for the R,A,S coordinates that will be placed in the label files.

• By default, the base name for the annotation file is 'aparc', so that the actual input annotation file is SUBJECTS_DIR/subject/label/lh.aparc.annot or rh.aparc.annot.
• A separate label file is created for each annotation index.
• The output file names can take one of two forms:
• If --outdir dir is used, then the output will be dir/hemi.name.label, where 'name' is the corresponding name in the lookup table in the annotation file.
• If --labelbase is used, name of the file is composed using the pattern: labelbase-XXX.label, where XXX is the zero-padded 3 digit annotation index. If labelbase includes a directory path, that directory must already exist.
• If there are no points in the annotation file for a particular index, no label file is created.
• The xyz (R,A,S) coordinates in the label file are obtained from the values at that vertex of the specified surface. The default surface is 'white'. Other options include 'pial' and 'orig'.
• The human-readable names that correspond to the annotation indices for aparc are embedded in the annotation file itself. It is no longer necessary (or possible) to specify the table explicitly with the --table option.

Details for 'seg' output file label numbers

The seg option causes the program to output a 'volume-encoded surface segmentation file'. This is simply the list of per-vertex label values (count = count of vertices), dumped into a file whose format looks like an FS volume file... which some other FS programs are equipped to load. (Ie: it is not actually volume data). See details below.

The label values stored in this situation may be recorded verbatim, or may be increased by an offset amount segbase. By default, these label values are intended to match the index for the label as found in $FREESURFER_HOME/FreeSurferColorLUT.txt; This requires that the annotation file base name be either aparc or aparc.a2005s, in order to invoke the following behavior: If aparc and hemi=lh, then segbase=1000, with segbase values for rh and for aparc.a2005s. This makes the index match that found in aparc+aseg.mgz. If the annotation is neither aparc nor aparc.a2005s, then segbase=0. This behavior can be overridden by manually specifying a segbase with --segbase.

Examples

Example 1

mri_annotation2label --subject LW \
  --hemi rh \
  --labelbase ./labels/aparc-rh

This will get annotations from $SUBJECTS_DIR/LW/label/rh_aparc.annot and then create about 94 label files: aparc-rh-001.label, aparc-rh-002.label, ... Note that the directory 'labels' must already exist.

Example 2

mri_annotation2label --subject LW \
  --hemi rh
  --outdir ./labels

This will do the same thing as above except that the output files will have names of the form lh.S_occipital_anterior.label

Bugs

If the name of the label base does not include a forward slash (ie, '/') then the program will attempt to put the label files in $SUBJECTS_DIR/subject/label. So, if you want the labels to go into the current directory, make sure to put a './' in front of the label base.

Testing

1. Start tksurfer:
   • tksurfer -LW lh inflated read_annotations lh_aparc
   • When a point is clicked on, it prints out a lot of info, including something like:
     • annot = S_temporalis_sup (93, 3988701) (221, 220, 60)
     This indicates that annotion number 93 was hit. Save this point.
2. Start another tksurfer and load the label:
   • tksurfer -LW lh inflated [edit label field and hit the 'Read' button]
   • Verify that label pattern looks like the annotation as seen in the tksurfer window from step 1.
3. Load label into tkmedit
   • tkmedit LW T1 [Load the label]
   • [Goto the point saved from step 1]

See Also

mris_label2annot, LabelsClutsAnnotationFiles

Reporting Bugs

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