Print

---

hi all,

I got different values when i used the call above on pve maps with a
binarized vs. non-binarized roi...
in avwstats++ with the -k option, does it weight the image with the mask or
do the min and max intensities in the mask act as a min and max threshold
for pulling out pve's ?

thanks,
Michelle



On 6/28/07, Jiansong Xu <[log in to unmask]> wrote:
>
> Thanks.
>
>
> > From: Matt <[log in to unmask]>
> > Organization: ma-tea.com
> > Reply-To: FSL - FMRIB's Software Library <[log in to unmask]>
> > Date: Thu, 28 Jun 2007 08:28:26 -0400
> > To: <[log in to unmask]>
> > Subject: Re: [FSL] volume of gray matter within a ROI
> >
> > Because you want to exclude values above and below 2.  In reality, the
> only
> > other values in the hard segmentation file will be 0 for empty space, 1
> for
> > CSF, and 3 for white matter.  I don't actually remember if avwstats++
> uses
> > an inclusive or exclusive threshold, so if using upper and lower values
> of 2
> > doesn't work, you could use 1.9 and 2.1 for the same effect.
> >
> > Peace,
> >
> > Matt.
> > -----Original Message-----
> > From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
> Behalf
> > Of Jiansong Xu
> > Sent: Wednesday, June 27, 2007 5:53 PM
> > To: [log in to unmask]
> > Subject: Re: [FSL] volume of gray matter within a ROI
> >
> > Thanks. Why both lower and upper threshold are 2?
> >
> >
> >> From: Matt <[log in to unmask]>
> >> Organization: ma-tea.com
> >> Reply-To: FSL - FMRIB's Software Library <[log in to unmask]>
> >> Date: Tue, 26 Jun 2007 20:03:33 -0400
> >> To: <[log in to unmask]>
> >> Subject: Re: [FSL] volume of gray matter within a ROI
> >>
> >> You could:
> >>
> >> A) Segment a structural scan on which you drew the ROI into grey
> matter,
> >> white matter, and CSF using FAST.
> >> B) Use avwstats++ <hard segmentation output> -l 2 -u 2 -k <your ROI> -V
> to
> >> find the volume of grey matter (value is 2 from the segmentation)
> masked
> > by
> >> your ROI.
> >>
> >> Peace,
> >>
> >> Matt.
> >> -----Original Message-----
> >> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
> Behalf
> >> Of Jiansong Xu
> >> Sent: Tuesday, June 26, 2007 7:25 PM
> >> To: [log in to unmask]
> >> Subject: [FSL] volume of gray matter within a ROI
> >>
> >> Dear Friend:
> >>
> >> I have defined a ROI and want to measure the volume of gray matter
> within
> >> this ROI. What is the procedure?
> >>
> >> Thanks a lot.
> >>
> >> Jiansong
>