[en] We have developed two kinds of data processing methods for co-registered PET and MR images. The 3D-brain surface, representing the cortical rim in the transaxial images, was projected on a 2D-plane by utilizing Mollweide projection, which is an area-conserving method of displaying the globe as a world map. A quantitative ROI analysis on the brain surface and 3D superimposed surface display were performed by means of the 2D projection image. A clustered brain image was created by referring to the clustered 3D correlation map of resting CBF, the acetazolamide response and the hyperventilatory response, where each pixel in the brain was labeled with the color representing its cluster number. With this method, the stage of hemodynamic deficiency was evaluated in a patient with the occlusion of internal carotid artery. The differences in the brain images obtained before and after revascularized surgery was also evaluated. (author)