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Hello,
I am conducting research using ECoG.
I want to accurately track the location of electrodes.
I am inputting data from a NIfTI file (size: 512, 512, 360, 1).
I already know the exact electrode location within the NIfTI file, e.g., (182, 274, 260).
The x, y, z values of this coordinate correspond to the raw fMRI scan, with x ranging from 0-512, y from 0-512, and z from 0-360.

I extracted the --vox2ras matrix from the 001.mgz file using mri_info.
I attempted to project the coordinates from the NIfTI file onto the generated pial surface, but I found a significant discrepancy.

What I need is not Talairach coordinates,
but a precise transformation of the electrode coordinates in the NIfTI space to their exact location on the subject's pial surface.
How can I achieve this?

Additionally, I noticed that the origin (0,0,0) of the generated pial surface does not align with the anterior commissure (AC).
I am curious about the coordinate system of the final mesh – is it simply the voxel-based x, y, z system, or is it in the RAS coordinate system?

Thank you.
Best regards,
Yonghyeon Gwon

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Yongheyon Gwon

Interdisciplinary Program in Neuroscience, Seoul National University, 

Human Brain Function Laboratory, Seoul National University Hospital

Seoul, Korea

E-mail: gngyong@hbf.re.kr , gyh0321@naver.com

Phone: +82-10-9706-3814

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