Automated Segmentation of Swine Skulls for Finite Element Model Creation Using High Resolution μ-CT Images

Abstract

Finite element (FE) analysis has been widely used to investigate bone responses to mechanical loading. Research in long bones has been straight forward because modeling of these bones requires only two material properties. Such an FE model may provide an adequate approximation of the anatomy for many cases. However, a more detailed model of skull bones is needed to accurately capture its complex structure of multiple bone pieces and the various mineral densities distributed throughout these bone pieces. Unfortunately, FE model development incorporating both complex geometries and anatomically accurate material properties is both computationally and labor intensive. In this study, a method is proposed to automatically segment micro-computed tomography ([Formula: see text]-CT) scan images of bone pieces to build an FE model of a full swine hemi-skull. Using the Digital Imaging and Communications in Medicine (DICOM) files from scanned bones, the complete geometry of each bone piece is recreated through seven customized processing algorithms. After assembling the bone pieces to form the skull, experimentally derived Young’s modulus values are correlated to grayscale values to produce a detailed FE model for accurate simulation. This detailed skull model can be used to predict strain/stress patterns in response to various loading regimes to facilitate research questions in fracture healing and growth, as well as bone tissue engineering and bone mineral density loss (e.g., osteoporosis).