Three dimensional (3D) modeling and visualization of the brain fusion images on the World Wide Web (WWW) is an effective way of sharing anatomic and functional information of the brain over the Internet, particularly for morphometry-based research and resident training in neuroradiology and neurosurgery. In this paper, 3D modeling, visualization, dynamic manipulation techniques, and the localization techniques for obtaining distance measurements of the inside and outside of the brain are integrated in an interactive and platform-independent manner and implemented over the WWW. The T1 weighted- and diffusion-weighted MR data of a stroke case which forms the subject of this study were digitally segmented, and used to visualize VRML-fused models in the form of polygonal surfaces based on the marching cube algorithm. Also, 2D cross sectional images were sequentially displayed for the purpose of 3D volume rendering, and user interface tools were embedded with ECMA script routines for the purpose of setting the appearance and transparency of the 3D objects. Finally, a 3D measurement tool was built in order to determine the spatial positions and sizes of the 3D objects.