The development of the bioengineering field has yield to the apparition of a new application of the Computer-Aided-Design, Bio-CAD, aiming to the use of computer models to represent biological samples and methods to simulate biological processes. Structural parameters allow to measure sample properties as osteoporosis degree of bones, suitability of biomaterials to be used as implants and transport and distribution of fluids into rocks for petrographic purposes among others. In this work a bibliographuc study is performed of structutal parameters mainly focussing on those related to the porosity and connectivity.