Hi Celine - The way this average is computed for pathstats.byvoxel.txt is by averaging the values for each one of the sample paths that are drawn by the MCM algorithm. This essentially "weighted" sinced voxels that more sample paths go through will be counted more than voxels that fewer sample paths go through.
a.y On Fri, 17 May 2013, cel...@nmr.mgh.harvard.edu wrote: > Hi Anastasia > I am very sorry I didn't see this email so it may be a doubloon with my > question I just post. > Indeed I am interested in a profile of the DTI metrics along the tract. So > if I take the average value of each section it can give me a kind of > profile, and so I was just wondering if taking a weighted metrics would be > possible in order to remove values that are a bit far from the highest > probability of the tract. > Thanks a lot! > Celine > >> >> Hi Celine - Since 5.2, there are 2 types of measures in the >> pathstats.byvoxel.txt file: The value at every point along the trajectory >> sampled at roughly the center of the bundle, or the value at every point >> along the trajectory averaged over the width of the bundle. Sorry, there >> are no other measures available at this point. If I understand correctly, >> you would like to see something like a profile of the measure of interest >> at every point along the trajectory? >> >> a.y >> >> On Mon, 6 May 2013, cel...@nmr.mgh.harvard.edu wrote: >> >>> Hi Tracula team >>> I am using tracula to study the corticospinal tract in a patient >>> population. I am wondering if there would be a way to have the different >>> DTI metrics from the whole tract at different depth/portion of the >>> tracts. >>> Something like the information given by the pathstats.byvoxel.txt file, >>> but for the whole width of the tract? >>> If not, do you see a way to sample the value of the diffusion metrics on >>> a >>> certain tract starting from the cortex (like with projfrac or projdist >>> with the WM surface)? >>> Thanks very much for your help >>> Celine >>> >>> >>> >>> >> >> >> > > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
