Hi Zohreh,


Both of those outputs are surface models, name_of_the_data_surf.vtk is a triangular mesh representation of the input segmentation while name_of_the_data _para.vtk contains the spherical mapping of the previous file into the unit sphere (it should look like a small sphere in the 3D window). 

I suggest you do the 3D slicer data loading and visualization if you have trouble looking at the data. The 3DSlicer training compendium can be found here http://www.slicer.org/slicerWiki/index.php/Documentation/4.0/Training and it is a great resource to have.


Hope that helps,
Beatriz