[FieldTrip] Alignment of MRI and estimated sources

Sylvana Schister sylvana.schister at utah.edu
Fri Aug 12 00:56:44 CEST 2011


Hello Fieldtrippers! 

I am having trouble getting meaningful results after performing source
analysis with DICS due to a misalignment of my MRI dataset. I am
relatively new to FT and I will really appreciate your help. 

I am using the 'standard_BEM' files provided in the tutorials. I manage
to realign the MRI to head coordinates using volumerealign, reslice and
segment it. Then, I use the modified MRI to compute the forward model. 

The problem arises when proceeding to ft_sourceinterpolate and
ft_sourceanalysis. As I understand, the 'mri' input to
ft_sourceinterpolate must be the output of FT_READ_MRI or the filename
of a MRI. The function crashes when using my realigned version of the
data, therefore I am using the original file, 'standard_mri.mat'. This
file contains no fiducials. No surprise the results are then messed up. 

How/ where do I need to specify the fiducials? Why can't I use the
aligned mri? 
What is the correct way to do this? 

Thank you so much for your help! 

Sylvana




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