Since human life is worthier than all things, efforts on virtual animation and visualization of human body's viscera, without surgical interference to diagnose a disease is very important. Recently, modern medical instruments are able to produce views which can be used for better diagnoses and accurate treatment. Various standards were formed regarding these instruments and end products that are being used more frequently everyday. Personal computers (PCs) have reached a significant level in image processing, carried analysis and visualization processes which could be done with expensive hardware on doctors' desktops. The next step is to try to find out proper solutions by software developers and engineers that help doctors to make decision by combining opportunities in these two scientific areas. The objective of the present study is to construct 3D models and present it to users on screen in personal computers by using data acquired from tomography and magnetic resonance instruments. In order to realize this objective, developing software is aimed. In the second and third sections, the data structures and processing of 3D volumetric data in digital format, 3D visualization techniques and theoretical subjects about methods and algorithms used are explained. In the forth section, explanations on developing a software package for the realization of the objective of the study, its usage and information about software development tools used are given. In the last section, the determinations made at the end of trials in this study, difficulties met and recommendations obtained in the light of the trial results are presented.