From: Bruce Fischl <fischl@nmr.mgh.harvard.edu>
Subject: Re: [Freesurfer] partial volume correction in mri_segstats
To: "Anthony" <slam_ono@yahoo.com>
Cc: freesurfer@nmr.mgh.harvard.edu
Date: Thursday, 5 March, 2009, 9:33 AM

Hi Anthony,

it should be more accurate (and more reliable in our studies). It 
estimates the volume fraction of each tissue
 class on the border of the 
structure, assuming it is mixed with adjacent classes by estimating the 
local mean of the two tissue classes, then computing the mixing 
coefficients that explain the observed intensity. Thus for example if you 
have a dark hippocampal voxel bordering ventricle it will compute that the 
voxel has a fair amount of ventricle in it.

cheers,
Bruce


On Wed, 4 Mar 2009, Anthony wrote:

> Hi all,
>
>
>
> In recon-all pipeline , mri_segstats runs with -pv mri/norm.mgz
> option ,as written from
> http://surfer.nmr.mgh.harvard.edu/fswiki/mri_segstats , it is used to
> compensate partial voluming. I wonder what exactly does this do, as the
volumes given by aseg.stats are different from
> aseg.mgz and why is it more accurate ? I will appreciate if anyone could
help to clarify this .
>
> Thanks
>
>
>
>    
  Get your new Email address!
> Grab the Email name you've always wanted before someone else does!
> http://mail.promotions.yahoo.com/newdomains/aa/
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer