External Email - Use Caution
I will try to to show you an example of the issue, so it may be clearer.
Let's say I have a contact in the left posterior insula with MNI
coordinates -33, -12, 13.
This corresponds to vertex 4983.
RAS coordinates on a pial surface: -35.1280 -10.8052 12.6963
RAS coordinates on an inflated surface: -14.9530 18.1240 -12.5924
As you can see from the enclosed figures, if I plot the coordinates on a
pial surface, they are indeed in the posterior insula.
If I plot the on the inflated surface, they are completely off.
2018-05-25 7:15 GMT+02:00 Giulia Liberati <giulia.liber...@uclouvain.be>:
> Thank you Bruce,
>
> Yes, this is what I did.
>
> Because the insular contacts are not in the insula anymore after I use the
> vertex to find the RAS coordinates for the inflated surface, my conclusion
> is that this only works with surface electrodes, not depth electrodes.
>
> Best wishes,
>
> Giulia
>
> On Thu, 24 May 2018 at 23:22, Bruce Fischl <fis...@nmr.mgh.harvard.edu>
> wrote:
>
>> Hi Giulia
>>
>> find the vertex index of the vertex you are interested in, then read the
>> surface whose RAS coordinates you want (e.g. the white or pial) and
>> lookup the RAS coords of the vertex at that index.
>>
>> cheers
>> Bruce
>> On Thu, 24 May 2018,
>> Giulia Liberati wrote:
>>
>> >
>> > External Email - Use Caution
>> >
>> > Dear FreeSurfer experts,
>> > How can you obtain RAS coordinates for an inflated surface when you
>> have vertex #?
>> >
>> > I am using the function read_surf('lh.inflated') to find the
>> coordinates of some electrode contacts
>> > located in the left insula. However, when I plot the coordinates using
>> plotPialSurf (iElVis), these
>> > locations are completely off (i.e., far outside from the insula).
>> >
>> > I don't understand what is going wrong.
>> >
>> > Any possible explanation?
>> >
>> > Thanks in advance!
>> >
>> > Giulia
>> >
>> >
>> >
>> >
>> > --
>> > Giulia Liberati, PhD
>> >
>> > Institute of Neuroscience (IoNS)
>> > Université catholique de Louvain
>> > Avenue Mounier 53 bte B1.53.02 à 1200 Woluwe-Saint-Lambert
>> > Claude Bernard; Etage 02; Local 0826; Site Bruxelles Woluwe
>> > Brussels, Belgium
>> >
>> >
>
> --
> Giulia Liberati, PhD
>
> Institute of Neuroscience (IoNS)
> Université catholique de Louvain
> Avenue Mounier 53 bte B1.53.02 à 1200 Woluwe-Saint-Lambert
> Claude Bernard; Etage 02; Local 0826; Site Bruxelles Woluwe
> Brussels, Belgium
>
--
Giulia Liberati, PhD
Institute of Neuroscience (IoNS)
Université catholique de Louvain
Avenue Mounier 53 bte B1.53.02 à 1200 Woluwe-Saint-Lambert
Claude Bernard; Etage 02; Local 0826; Site Bruxelles Woluwe
Brussels, Belgium
_______________________________________________
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.
