[CT-tomometry. Part 1: Inhomogenities of tissues--treatment planning (author's transl)].

By experiments at the CT-total-body-scanner we have related to each other the delta-Nrs., chemical constitution, and density of chemical compounds and of tissues of men. For the bone tissue the relation between delta-Nr., Ca-concentration, and density is given in tabular. The uncertainties of the relations evaluated by experiments are within the acceptable values for the most cases occurring in treatment planning. In the second part we will extend the relations to the application of contrast enhancement in the diagnostic.