[FieldTrip] why does my functional data not match to template mri?

[Schoffelen, J.M. (Jan Mathijs)]

Hi Chen,

The interpolation only works fine if both objects are in the same coordinate system. Since the template MRI is expressed in a different coordinate system than the source reconstructed results, you get the results that you are seeing. In other words, this is a user error. If your sourcemodel has been derived from a template model (derived from the template MRI) as well, you can replace the source.pos with the template’s dipole positions, in which case I’d expect the interpolation to the template MRI to work.

Jan-Mathijs


J.M.Schoffelen, MD PhD
Senior Researcher, VIDI-fellow - PI, language in interaction
Telephone: +31-24-3614793
Physical location: room 00.028
Donders Centre for Cognitive Neuroimaging, Nijmegen, The Netherlands



On 4 Mar 2019, at 09:14, Chen Junhao <cjh940224 at hotmail.com<mailto:cjh940224 at hotmail.com>> wrote:

Dear fieldtripers,
   I got some problems when I was conducting source reconstruction on MEG data. I followed this tutorial (http://www.fieldtriptoolbox.org/tutorial/beamformingextended/) but I had reslice the individual mri before segmentation and creating headmoel. I had checked the completed headmodel and sourcemodel based on MNI space, they were fine and matched. The problem is when I interpolated the functional data (source) on individual mri, it looks fine (figure attached: interpolate_on_individual_mri). But when I interpolated the source on template mri, the functional data and anatomy data did not matched well. The sagittal pane of functional data was plotted on the coronal plane of anatomical image, and so forth (figure attached: interpolate_on_template_mri). One of the tutorial said that if I created sourcemodel based on MNI space, I do not need to interpolate the functional data, but I am still worried about the accuracy. My MEG data were collected from ‘4d/bti 148channel’.

  Thank you very much for your time and consideration. Looking forward to your reply.

  Best wishes,

  Chen

<interpolate_on_individual_mri.jpg><interpolate_on_template_mri.jpg>_______________________________________________
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