Dear freesurfer experts,
I have some questions about the coordinates conversion, and the relationship between several types of coordinates.
First of all, I’d like to confirm whether the coordinates reported in the results summary are based on MNI305 space?
Second, I plan to combine multi-modalities data, therefore I would like to use the peak vertex in the surface as a seed to do additional volume-based analysis. I have the vertex index, vertex ras, MNI coordinates reported in the summary text, but how can I get the correct and corresponding volume coordinates in MNI space, particularly in MNI152?
I read the page about the freesurfer coordinate system, they mentioned several cases about the transformation, but I still cant figure out what is the correct way in my case. Moreover, I tried the mni305 to mni152, but when I double checked the coordinates in mni152 space, the peak was no longer corresponds to the region reported in the mni305 space. So I sure there must be something wrong.
Finally, would anyone offer me a explanation about the relationship between surface RAS, volume RAS, MNI* RAS, Vertex MNI, Volume MNI coordinates? It quite confused me.
Thanks in advance,
Best regards, Ting