Cortical Mesh MNI format

Description 

The following MATLAB code will load MNI cortical mesh format into matlab. It only read ASCII-based MNI format. MNI surface mesh format  always ends with *obj extension.

MATLAB Codes and sample cortical mesh (MATLAB 6.1. implementation)

• mni_getmesh.m loading triangle MNI mesh format into MATLAB.
• Outsurface.obj sample cortical surface mesh.
• sphere.obj cortical surface flattened onto a sphere.

[tri,coord,nbr,normal]=mni_getmesh('outersurface.obj');

load thickness.data;

output=hk_smooth(thickness',tri,coord,nbr,1,200);

trisurf(tri, coord(1,:),coord(2,:),coord(3,:),output);

• coord (3x40962) gives Cartesian coordinates of 40962 nodes.
• nbr (40962x6) gives neighboring node indices. Each node has up to 6 neighboring nodes. First 12 nodes have only 5 neighbors while the remaining 40962-5 nodes have 6 neighbors.
  
• normal (3x40962) gives the normal vectors of the cortex.
• tri (81920x3) gives node indices that forms each of 81920 triangles.

Documentation
The cortical mesh format has been used in the following  studies.

• Chung, M.K., Robbins, S., Evans, A.C. 2005. Unified statistical approach to cortical thickness analysis. Information Processing in Medical Imaging (IPMI). Lecture Notes in Computer Science (LNCS) 3565:627-638. Springer-Verlag.
• Chung, M.K., Robbins,S., Dalton, K.M., Davidson, Alexander, A.L., R.J., Evans, A.C. 2005. Cortical thickness analysis in autism via heat kernel smoothing. NeuroImage 25:1256-1265

Images

Created 05/09/2006.