convert NIfti file (nii.gz) to (.vtk)file

I am working with MRI Nifti dataset and I would convert it to .vtk meshes file.
I installed the ITK-SNAP and 3cd converter.
but there is a problem
exemple : as you see in the picture 1 I couldn’t open the .vtk file ( I converted it with (c3d file.nii.gz -o file.vtk) also with itsknap (which i saved the image output as VTKfile)

and if I want to show it with paraview I couldn’t see anything as you see in the picture 2

See that “Outline” dropdown right in the middle of your ParaView toolbars? What if you change it to “Surface” or “Surface with edges”?


the same thingCapture%20d%E2%80%99%C3%A9cran%20de%202019-11-06%2019-47-33

With that dropdown, you are changing how the data is displayed, the “representation”. It looks like you have successfully loaded a cube of data. Does “Volume” give you something more interesting? I suggest you look at the ParaView Guide for some hints on interacting with your data - using the “Clip” or “Threshold” filter, for example.