fNIRS Montage Coregistration Problems

When importing a raw .nirs file into Brainstorm, our montage is not properly coregistered and we can’t figure out how to align it correctly.

The montage appears rotated ~90° counterclockwise from its proper orientation, and it is also scaled incorrectly: the middle optodes phase through the head mesh while the outer optodes float outside the scalp surface.

We’ve tried importing anatomy using Brainstorm’s automatic registration function, and manually defining NAS/LPA/RPA, both of which result in the same issue. By opening the montage in MATLAB and applying a rotation matrix, we can correct the Z-axis rotation, but there are still obvious scaling/coregistration errors.

Are we missing something? Happy to share screenshots or additional file details if that would help diagnose the issue.

Thanks for all the help.

raw import:

Hello,

Could you share the brainstorm subject and .nirs file so we can do some test ?

Regards

Edouard