In this paper we compare confocal apparatus tomography and computer tomography for medical use. Two aspects are illustrated: the process of image visualization and the dose deposition. The latter aspect is a damage factor of the object under investigation; it is why the data collection time is evaluated. Two principal tomography schemes are described and the expressions connecting the collected signal value with the object's internal structure are given. Based on the expression, the process of image visualization is described and the dose deposition is calculated for both cases. The object's classification is introduced to choose the optimal experimental scheme for the object under study.