Recently, the term BioCAD has appeared to refer to the modeling of biological processes. This work focuses on the analysis of structural properties such as porosity of bioimplants for bone reconstruction. Specifically, we present a method that, using 3D microCT images, simulates the behavior of a porosimeter, i.e. an instrument to measure the porous structure of samples. After segmentation, we apply a process, based on connected component labeling and skeleton computation, which produces a result comparable to the real porosimeter experiment.