髋臼区域皮质骨厚度分布特征的三维图像测量*☆

背景：课题组前期研究建立了采用正常人体的CT数据构筑三维模型研究皮质骨厚度的空间分布的方法。目的：根据髋骨皮质骨三维厚度分布规律对髋臼区域的皮质骨厚度进行分区。方法：使用Mimics对8名健康志愿者髋骨CT图像进行分割提取皮质骨并建立几何模型。以A平台提供的二次开发语言PCL编写皮质骨厚度测量的新算法。获得厚度数据后根据各厚度范围皮质骨分布面积的大小，采用聚类分析的方法对测得的厚度范围进行分组。结果与结论：髋骨皮质骨厚度介于0.44~4.00 mm，采用聚类分析的方法发现可分为0.44~1.133 mm、1.133~1.826 mm及1.826~4.00 mm 3组，按照这3组厚度范围对髋骨模型进行渲染后发现整个髋骨的皮质骨的较厚部位可分为明显的三组皮质骨束，第1组沿弓状线延伸至耻骨联合，第2组从臼顶延伸到髂结节，第3组分布在坐骨大切迹上下。说明在髋臼区域皮质骨较厚的部位可大致分为3组，其部位与应力集中点点基本吻合。

The thickness distribution characteristics of cortical bone around acetabulum measured by three-dimensional image

BACKGROUND: Preliminary studies have established the method to research the spatial distribution of cortical bone thickness through the three-dimensional model based on the CT data of the normal body.  OBJECTIVE: To make division of the thickness of cortical bone around the acetabulum according to the three-dimensional thickness distribution of the hip cortical bone. METHODS: The cortical bone was extracted and the geometric model was established through the segmentation of eight healthy volunteers CT image by Mimics. The new algorithm of cortical thickness measurement was determined by Patran Command Language provided by PATRAN platform. After the thickness data were obtained, we made a division of the thickness area by cluster analysis method according to the distribution size of the cortical bone.    RESULTS AND CONCLUSION: The cortical thickness of acetabulum was between 0.44 mm and 4.00 mm. Cluster analysis showed that it could be divided into 0.44-1.133 mm group, 1.133-1.826 mm group and 1.826-4.00 mm group. According to the thickness of the three groups, the model was rendered, and then we found that the thicker parts of the cortical bone could be divided into three cortical bone beams. The first group was extended from the arcuate line to the pubic symphysis. The second group was extended from the acetabular roof to iliac nodules .The third group was around the ischium notch. There were three thickest positions throughout the thicker parts of the cortical bone around acetabulum. The positions were consistent with the high stress points.