Shape classification techniques for discrete 3D porous media. Application to trabecular bone.

The clinical process used to screen osteoporosis is the Bone Mineral Density (BMD). Since this density measurement does not cover the entire diagnosis range, work is being carried out on the segmentation of the bone and other complex porous media to provide quantitative information about their microarchitecture. Two shape classification techniques have been recently proposed in the literature. In this paper we compare these different methods and propose a new original rod/plate classification technique. The efficiency of the 3 processes is then studied on test vectors composed of both rods and plates, then applied on real trabecular bone samples. Results of this study emphasize the pros and cons of the 2 published techniques, and discuss the improvements of the new region-growth-based method. Finally, the interest of such a tool in osteoporosis screening is discussed.