Micro-CT image of C1 carbonate rock and extracted networks (Dong and Blunt, 2009, DOI: http://dx.doi.org/10.1103/PhysRevE.80.036307)
The image can be visualised by opening the Nrrd header file C1.nhdr in visualization software such as Paraview or ImageJ (http://fiji.sc/Fiji), You can also open the C1.nhdr file in a text editor to see the image and voxel sizes.