Thank you both.
How can I deal with partial volume in this case? Would it be possible to use 
the partial volume tool for PET on my MD volumes? Sorry if it is a silly idea.
Best Wishes,Shane

On Friday, August 11, 2017, 6:19:45 PM GMT+1, Yendiki, Anastasia 
<ayend...@mgh.harvard.edu> wrote:

Agreed, especially so with MD. Keep in mind that you¹re upsampling MD from
a lower-res (diffusion) space to a higher-res (T1) space, so it should be
smooth already, relatively to measure derived from the T1. And MD varies
pretty smoothly (it¹s a mean of 3 things, after all).

On 8/11/17, 1:11 PM, "Bruce Fischl" <fis...@nmr.mgh.harvard.edu> wrote:

>Hi Shane
>
>not really - it totally depends on the size of the effect you are looking
>for. I would be *very* careful about partial volume effects though
>
>cheers
>Bruce
>On Fri, 
>11 Aug 2017, Shane Schofield wrote:
>
>> Appreciate it Dr Bruce. Do you have guidelines for smoothing MD?
>> 
>> Dr Yendiki, I am trying to investigate whether cortical MD can be a
>>marker
>> of neurodegeneration. The idea is that during the early stages of a
>>disease,
>> cellular microstructure may breakdown before cortical thinning occurs.
>>This
>> results in "less" barriers against diffusion resulting in an increase of
>> MD. 
>> 
>> 
>> On Friday, August 11, 2017, 5:49:40 PM GMT+1, Bruce Fischl
>> <fis...@nmr.mgh.harvard.edu> wrote:
>> 
>> 
>> Hi Shane
>> 
>> you probably don't need cvs as it is more to extend the surface-based
>> registration to the entire volume. Here you just need the surface-based
>> registration I believe. Use mri_vol2surf to sample the FA onto the
>>surface.
>> After that it is identical to a thickness study
>> 
>> cheers
>> Bruce
>> 
>> 
>> 
>> On Fri, 11 Aug 2017, Shane Schofield
>> wrote:
>> 
>> > Thanks Dr Yendiki.
>> >
>> > I am more interested to compare MD in grey matter regions by putting
>>the
>> MD on the surface, and then do a glmfit type of comparisons. Is that OK?
>> Would you recommend me
>> > to smooth the data after spatial normalisation? I have also used the
>> mri_cvs_register as described on the tutorial.
>> >
>> >
>> > On Friday, August 11, 2017, 7:03:49 AM GMT+1, Shane Schofield
>> <shane.schofi...@yahoo.com> wrote:
>> >
>> >
>> > Hi DTI Experts,
>> >
>> > Is it sensible to do comparisons of MD on the cortex surface like a
>>normal
>> cortical thickness comparisons between group? If the answer is yes, are
>> there recommended on
>> > smoothing ?
>> >
>> > DT_RECON has been completed in Freesurfer.
>> >
>> > Thank you.
>> >
>> >
>> >
>> _______________________________________________
>> 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.
>> 


_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
_______________________________________________
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.

Reply via email to