Meshing issues with MergeSurf

[kenzo0619]

Hi @Francois

I am working on source estimation with FEM methods, the Duneuro reported error with coordinate is outside the grid. As it may caused by meshing, so I would like to remesh it with isomesh. With mergesurf method, it reports errors, would you mind to take a look at ?
The mesh components (white,gray,csf,skull,scalp) can be download via the link for reproducing the result.

[tmedani]

Hi @kenzo0619

@kenzo0619

I am working on source estimation with FEM methods, the Duneuro reported error with coordinate is outside the grid. As it may caused by meshing

This issue is not caused by the meshing but by the position of the source space.
Could you tell us more about the model that you are computing:
Is it MEG or EEG?
Have you used the volume grid for the source space?

@kenzo0619

so I would like to remesh it with isomesh. With mergesurf method, it reports errors, would you mind to take a look at ?

which option have you used : iso2mesh or iso2mesh2012?

I checked the surfaces that you shared, using the "iso2mesh-2021", then "MergeMesh", with the default values, and it works... here is a view of the mesh:

Could you update iso2mesh and follow the same steps as I did.

Thanks,

Takfarinas

[kenzo0619]

hi @tmedani

Thanks for the reply.

This issue is not caused by the meshing but by the position of the source space.
Could you tell us more about the model that you are computing:
Is it MEG or EEG?
Have you used the volume grid for the source space?

It is high-density EEG (256 channels EGI system), since we are interested in deep brain structures(cerebellem/brainstem/basal ganglia), I used MRI volume for the source space.

which option have you used : iso2mesh or iso2mesh2012?

I have tried both iso2mesh and isomesh2021 with mergeSurf. The mergeMesh worked, but with 0.001 max tetrahedral volume, the error from Duneuro is the same. with 0.0001 it reported error : killed.

Any other suggestion on the error: coordinate is outside the grid for headmodeling?

Many thanks

[tmedani]

@kenzo0619

The mergeMesh worked, but with 0.001 max tetrahedral volume, the error from Duneuro is the same. with 0.0001 it reported error : killed.

using the MaxVol at 0.0001 will generate a very fine mesh and it may crash your memory. You don't need to go up to this resolution.

@kenzo0619

Any other suggestion on the error: coordinate is outside the grid for headmodeling?

This is due to the placement of the dipoles, when you generates the volume grid,
which option are you using to generate the dipoles?
The option that you are using generates dipoles which are outside of the brain area, which lead to the DUNEuro error.

https://neuroimage.usc.edu/brainstorm/Tutorials/TutVolSource#Compute_a_volume_head_model

I may recommend to use the first option.

Could you display the source space that are you using for visual inspection? (click on the "Preview" ) and then add the FEM mesh on it.