醫學影像的曲面模型(Surface model)重建對於醫學工程領域來說，是非常重要的工具，尤其是在骨科手術中，常會以患者骨組織的幾何模型來協助術前的診斷與規劃，因此骨組織模型的重建，為首要的步驟，然而骨模型的重建流程含括了醫學影像與幾何模型技術，重建步驟複雜且需耗費許多時間。本研究目標為整合「影像組織分離技術」以及「曲面模型重建技術」，發展電腦斷層影像的骨組織模型重建程序，以提高骨組織模型的重建效率。「影像組織分離技術」方面，以疊代式區域成長法為基礎，發展半自動化的骨組織分離程序，本程序能夠於不同的骨頭組織上自動分配種子區域，正確的完成骨組織分離，另外適用性高以及分離效率佳也是本程序最大的優勢之一。「曲面模型重建技術」方面結合了模型簡化、網格四邊化、網格後處理以及特徵邊搜尋等技術，使能夠於網格化後的骨網格模型上自動規劃出曲面的四邊架構曲線，並經由此架構曲線重建曲面模型。最後整合以上程序，以多組實際的人體骨組織影像為例，重建其曲面模型，以證明其本研究之可行性。Surface model reconstruction is an extremely important technique in biomedical engineering as it can assist in implant design and preoperative planning of orthopaedics. However, bone model reconstruction is composed of medical image process and computational geometry algorithms, which is complex and difficult to be integrated. Therefore, the objective of this study is to integrate above approaches into a procedure to simplify the operation course and improve overall efficiency of bone model reconstruction. The procedure can be divided into two steps: (1) CT images segmentation: the proposed process is based on iterative regions growing. In which, the seed regions generation algorithm is proposed to automatically generate an initial region on each bone of interest. Finally, the individual bone region will be extracted by seed regions expanded iteratively. (2) Surface model reconstruction: a method for building quadrilateral network of curves automatically from triangular mesh is proposed in this study, which mainly includes mesh simplification, quadrangulation and curve net generation. When curve net is produced, it can be served as the framework of automatic surface reconstruction. Finally, several sets of bone images have been presented to demonstrate the feasibility of this integrated procedure.
