A method for multimodal 3-D image registration with external markers

A method for multimodal 3-D image registration using external markers is presented. The overall image transformation is parametrised with three rotation angles (Euler angles), three translation and three magnification parameters. These parameters are estimated from measurements of the corresponding positions of the point markers in 3-D space. After all marker positions have been transformed in the same modality, a x² function of these parameters, defined in terms of the squares of distances of corresponding markers in two modalities is minimised using a sequence of minimisation techniques I the Simplex method followed by a variable minimisation. Some quantitative features of this method are studied.