Bruce, You had posted that there is a 'backwards compatibility flag' regarding control points manually specified to the aseg normalization in Freesurfer version 5.1 (see your thread from 1/27/12 below). You said that Nick might know about this flag.
I too had noticed very different behavior after adding control points in v5.0 and v5.1, as many more regions were tagged as white matter in v5.1 than in v5.0. Would anyone know if this flag exists and how to use it? Thanks, Chris Re: [Freesurfer] control point guidanceBruce Fischl Fri, 27 Jan 2012 11:58:38 -0800 Hi Mikeit's a bit hard to state the region of effect for the control points. Essentially we go through and label voxels as control points or not based on their intensity, intensity gradient and connectivity (that is, the must be 6-connected to other control points) then build a Voronoi diagram and each control point sets the scaling for its Voronoi triangle. Thus if you have a control point surrounded by others its region of effect is small, but one control point all by itself can have a large region of effect.Also, 5.1 applies the manually specified control points to the aseg normalization (norm.mgz), whereas older versions didn't. Not everyone is happy with this, so I think there is a backwards compatibility flag. Nick would know.Bruce _______________________________________________ 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.
