Segmentation procedure for the generation of a 3D model and solid replica of a human skull

The present study describes a strategy to produce patient-specific skull base rep-lica with realistic shapes, starting from radiological images. Several papers aim to highlight the clinical value of patient-specific three-dimensional (3D) models, ob-tained segmenting multidetector computed tomography (MDCT) images, for preoper-ative planning in general surgery, for physician training and for didactics targets. In this study, segmentation and 3D model generation were performed using a semiautomatic tool developed in the EndoCAS centre. The segmentation procedure is based on the neighbourhood connected region-growing algorithm that, appropri-ately parameterized for the anatomy of interest and combined with the optimal seg-mentation sequence, generates good-quality 3D images coupled with facility of use. Using a touch screen monitor, manual refining has been added to segment struc-tures unsuitable for automatic reconstruction. The goal of the present work consists in providing and visualizing quantitative geometrical and topological information on the anatomy of a cranium, starting from a MDCT dataset, and to develop a detailed solid replica that allow to improve the com-prehension of anatomy and the dimensions of deep structures of a skull base. Ana-tomical structures of little size - e.g. foramen rotundum, foramen spinosum, lamina cribriformis, hypoglossal canal - were replicated in detail. Furthermore our 3D virtual model permits to well distinguish pneumatized bones; in particular nasal cavities and paranasal sinuses were minutely computer-generated. We consider that our methodological approach to reproduce virtual and solid an-atomical models can represent an useful didactic tool, both for undergraduate and postgraduate students.