On Mon, Apr 2, 2012 at 4:47 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu> wrote:

why don't you use the gray/white contrast map that freesurfer produces?

On 04/02/2012 04:24 PM, John Fredy wrote:

Dear Douglas and David,

I am trying to know the gray-white contrast in images from epileptic patients. In know that I can use the freesurfer surface to obtain the coordinates for the interface between gray-white substance, but some help is welcome because the paper that I read introduce elements like use the data 0.5 before and 0.5 after the interface

How I can convert the surface to voxel coordinates?

How I can obtain the data (0.5 mm) out of the resolution of my images (that is 1 mm)?

Any interpolation suggestion?

Exists some code that I can use

Thanks in advance

John Ochoa
Bioingeniería
Universidad de Antioquia

On Mon, Apr 2, 2012 at 12:12 PM, Bruce Fischl <fischl@nmr.mgh.harvard.edu <mailto:fischl@nmr.mgh.harvard.edu>> wrote:

Hi John

Doug and David (ccd) can point you in the right direction once you
are done with your surface recons

cheers
Bruce

On Mon, 2 Apr 2012, John Fredy wrote:

Dear Bruce,
I have interest in the tools that you mentioned

Best

John Ochoa

On Sat, Mar 31, 2012 at 5:31 PM, Bruce Fischl
<fischl@nmr.mgh.harvard.edu <mailto:fischl@nmr.mgh.harvard.edu>>

wrote:
Hi John

we can provide that for you if you download and install
FreeSurfer, then run recon-all on your data. We also provide
tools for computing gray/white contrast once recon-all
has been
run.

cheers
Bruce

On Sat, 31 Mar 2012, John Fredy wrote:

Hello all, I am looking for a white-gray matter contrast
algorithm

I see the publication: Individual Differences in Verbal
Abilities Associated
with Regional Blurring of the Left Gray and White Matter
Boundary

http://www.ncbi.nlm.nih.gov/pubmed/22031871

But,how I can obtain the coordinates of the interface
between gray and white
matter?

Thanks in advance

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MGH-NMR Center
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