Bones are heterogeneous in terms of the distribution of material. Visualizing the distribution of material on a computer screen in three dimensions helps to understand the heterogeneity of bones. However, there is a limitation because it is not observing the real thing. To resolve this problem, in this study, we propose a method to visualize the heterogeneity of a bone using a 3D printer.
First, the region of interest of a bone is segmented from a set of CT images. The shape of the bone is represented by cubic triangular Bézier patches. The density of the bone is represented by B-spline volume functions. The density is evaluated from the HU value of CT images using the formula proposed by Wirtz et al. The shape of the bone is converted into a triangular mesh, and the color value converted from the density is assigned to each node of the mesh. The mesh is save as a PLY file, and then printed using a color 3D printer.
In addition to visualize the bone density, the proposed method can be used to visualize various analysis results. This will help to understand the analysis results.