Hi David - The path.map file is the maximum a posteriori (MAP) estimate of the path. That is, of all the paths that were generated by the algorithm and summed to create the posterior distribution path.pd, this is the path that on average over all its voxels maximizes the posterior probability given the data. Thus this is just a single path (a one-dimensional curve) and not a thresholded version of path.pd. You could create a new ROI by thresholding path.pd at your desired level if you wanted to get statistics of the FA, MD, etc at a new threshold.
Hope this helps, a.y On Tue, 23 Aug 2011, David Coynel wrote: > Dear experts, > Could you please tell me how the path.map for a given pathway is computed, > and especially if it is a thresholded version of the posterior distribution > path.pd. In this case, would it be possible to re-run the tract-statistics > using different path.map files ? > > Thank you > Dr. David Coynel > Division of Cognitive Neuroscience > > University of Basel > Birmannsgasse 8 > 4055 Basel - Switzerland > > david.coy...@unibas.ch > tel: +41(0)612.670.240 > > Am 23.08.2011 um 04:03 schrieb Anthony Dick: > > The subcortical segmentation identifies subcortical structures > such as > thalamus, basal ganglia structures, hippocampus, amygdala, and > cerebellum. The cortical parcellation delineates different areas > of the > cortex, such as the superior temporal sulcus, the central > sulcus, the > pars triangularis, opercularis, and orbitalis of the inferior > frontal > gyrus. A recommendation is to get a copy of the Duvernoy atlas, > which > covers definitions of different parts of the cortex. The Mai > atlas is > good for learning subcortical structures. > > On 8/22/11 9:45 PM, Kenichiro Tanaka wrote: > Hello All, > > > I have a question about "segmentation" and > "parcellation". > > > What is the difference between the subcortical > segmentation and the > > cortical parcellation? > > Especially I do not understand the difference > between subcortical and > > cortical and between segmentation and parcellation. > > I tried to read FreeSurfer Wiki, but I did not > understand it well. > > Could you tell me it? > > > Thanks. > > > Kenichiro Tanaka. > > > _______________________________________________ > > 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. > > > > > -- > Anthony Steven Dick, Ph.D. > Assistant Professor > Department of Psychology > Florida International University > Modesto A. Maidique Campus DM 296B > 11200 S.W. 8th Street > Miami, FL 33199 > Phone: 305-348-4202 > Fax: 305-348-3879 > Email: ad...@fiu.edu > Webpage: http://www.fiu.edu/~adick > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
