Registration of medical images is technique, which is developing with new hybrid diagnostic imaging systems. Nowadays is a trend in image registration focused on monomodality and multimodality images registration. The first part of this master’s thesis is intent on present basic information about image registration. Concretely is intending on image transformation, interpolation, criteria function and at optimalization. Further part present realized Optical Flow technique and used “Demon” algorithm for image registration. The next part is focused on presentation of program solution and GUI. In the last section of this master’s thesis is verifying of created program on usual images and real CT images.