Re: [Freesurfer] Segmentation Volume Data

2008-12-01 Thread Bruce Fischl
Hi Mishkin, the partial volume correction considers every voxel that borders a voxel with a different label. It then computes what other label is it's most common nbr, then computes the mean non-border intensity for the central and nbr labels in a window (7x7x7 I think), and uses these two mea

Re: [Freesurfer] Segmentation Volume Data

2008-12-01 Thread Mishkin Derakhshan
Hi, Are the details of the partial volume corrections described anywhere on the wiki, I couldn't find anything? Is it just a certain percentage of the volume that is disregarded depending on the surface area, or is there a probabilistic labeling of the structures somewhere? Is it possible to get a

Re: [Freesurfer] Segmentation Volume Data

2008-11-25 Thread Doug Greve
The aseg.stats is computed with a partial volume correction at the boundaries of the structures, tkmedit just counts voxels. Yuan Xu wrote: Hi FreeSurfer: when I compare a brain structure volume count on the aseg.stats files with a volume of same structure measured using tkmedit "Se

[Freesurfer] Segmentation Volume Data

2008-11-25 Thread Yuan Xu
Hi FreeSurfer:  when I compare a brain structure volume count on the aseg.stats files with a volume of same structure measured using tkmedit "Segmentation Label Volume Count" feature to display on TkMedit Tools window. They are closer but not the same, usually about 3 to 10% difference. Why? Th