This paper proposes morphological descriptors representing the degree of skull deformity for craniosynostosis in head CT images and a hierarchical classifier model distinguishing among normal and different types of craniosynostosis. First, to compare deformity surface model with mean normal surface model, mean normal surface models are generated for each age range and the mean normal surface model is deformed to the deformity surface model via multi-level threestage registration. Second, four shape features including local distance and area ratio indices are extracted in each five cranial bone. Finally, hierarchical SVM classifier is proposed to distinguish between the normal and deformity. As a result, the proposed method showed improved classification results compared to traditional cranial index. Our method can be used for the early diagnosis, surgical planning and postsurgical assessment of craniosynostosis as well as quantitative analysis of skull deformity.
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 T<sub>1</sub> 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.