Hi Lulu - We actually have an automated method to do this. You can read about it in our paper: http://www.frontiersin.org/Neuroinformatics/10.3389/fninf.2011.00023/abstrac...
And you can learn how to use it here: http://surfer.nmr.mgh.harvard.edu/fswiki/Tracula
If you wanted to do this manually, you wouldn't draw ROIs at the endings of the tracts, but deeper in the white matter. This is one paper on this: http://www.ncbi.nlm.nih.gov/pubmed/17481925
Hope this helps, a.y
On Sat, 12 Oct 2013, lujiao luo wrote:
Dear experts, I was trying to define the ILF(inferior longtitudinal fasciculus), IFOF(inferori fronto-occipital fasciculus), arcuate fasciculus, and corpus callosum (CC). But I am not very familiar with the structure of the cortex. So I am considering that if I can segment some roi files from freesurfer aseg+aparc.annot file and changing them into .nii.gz file, Then use these rois as the seed of fiber tracking. Would you mind teaching me which rois I choose for each fiber tract if this way is possible? Another question is about the meaing of labels with a wm- begining (e.g. wm-lh-G_frontal_superior) in the look-up table. Does it represent the white matter within the lh-G_ frontal_ superior or represent all white matter that passed through lh-G_frontal_superior? Thanks so much for your concern. Yours, Lulu