CAT is a new non-destructive technique of analysis extending considerably the possibilities of conventional radiography. CAT provides sections through the object, while radiographs are shadowgraphs where all details are projected in one plane. Peculiarly remarkable is the high resolution of densities by CAT, reaching values of 0.1% in medical application. CAT provides unique possibilities of examination in those cases where details in the interior of strongly absorbing coverings are to be made visible.