Hi,
we did a TMS mapping experiment and now have a collection of target points on the scalp with coordinates, the measured motor evoked potentials and vectors describing the coil orientation. Our goal is to visualize the stimulation sites on the "brain surface".
The general problem is shown in Fig. 4 in the following publication: Motor area localization using fMRI-constrained cortical current density reconstruction of movement-related cortical potentials, a comparison with fMRI and TMS mapping, Alberto Inuggi et al., Brain Research ( 2010 ) 68 – 78, shortened Pubmed link: goo.gl/rqFf4
It is best if I describe our problem using that figure, so you have a visual representation. So, we have the point Ts, which is our stimulation site. Because we also know the exact coil orientation we have the vector n too. That is the difference between the solution in the paper and our problem. That is why we do not need the Curry origin as a construct to project the targets Ts onto the CSF. In theory we only need to know the coordinate TnL where the vector n dissects the CSF surface.
Big question: Is this possible in FSL or some other freely available software? We don't have Curry and it is quite pricey. We do have BrainVoyager users and also FSL users, but they don't know if it is possible to do this.
Of course this is only one way to present this. I already have a 2D image of the mapping with the grid indices as coordinates. Alternatively I could project this image onto the brain, but this seems to me as a more complicated way.
Any pointers into the right direction would be welcome.
Manuel Hewitt
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