Computer Assisted Tomography (CAT) scanning was introduced as a tool for the development and/or testing of methodologies aimed at the non-destructive characterization of porous media ten years ago. This work summarizes ten years of our experience in this area. The conclusions drawn in this paper are based on the analysis of over one hundred pieces of core. The cores represent both unconsolidated media, such as heavy oil reservoirs and various sandpacks, and consolidated reservoirs including two sandstone reservoirs, one dolomitic sandstone reservoir, one limestone reservoir and over six dolomitic reservoirs. It was necessary to perform extensive calibration runs including several hundred tests on reservoir rock and other samples. Some of the information was obtained using dual energy scanning. Experience on the operating procedures of the CAT scanners was also obtained. The summarized results are presented here.