额窦引流通路可视模型构建及空间方向分析

Construction and spatial directions analysis of digitized visible model of frontal sinus drainage pathway

背景:正确理解鼻窦解剖的个性特征是提高额窦手术疗效和减少手术并发症的关键,二维CT影像对术前评估额窦周围气房及引流通路十分局限。目的:构建额窦引流通路及相关结构可视模型,并分析其内镜下空间方向。方法:依据1例患者冠状位CT扫描数据,通过AutoCAD(computer aided design)、自由设计大师(Moment of Inspiration,MOI)和Sketch Up软件构建FSDP及相关结构的三维可视模型。CT影像与内镜下影像对比,内镜仰角60°观察视觉空间内空间方向的变化。观察额窦和周围气房的引流通路及空间位置关系,模拟0°内镜空间下手术进程。结果与结论:成功构建FSDP及相关结构可视模型;视觉空间方向发生改变,这种变化受透视规律的影响;模型可显示额窦和相邻气房的引流通路及相互关系,通过模拟内镜下手术过程,可建立正确视觉空间关系。结果证实二维影像、三维立体、内镜空间三者存在差别,再次验证内镜透视规律的存在,强调并提出视觉空间理念;可视模型有利于对额窦引流通路的理解,并可用于内镜手术的解剖教学和模拟。

BACKGROUND： Correct understanding of accessory nasal sinuses anatomic features is important for improving operative success and reducing complications. Two-dimensional CT images limit preoperative evaluation of frontal sinus cells and drainage pathway. OBJECTIVE： To develop the digitized visible model and to analyze the endoscopic space of the frontal sinus drainage pathway （FSDP） and related structures. METHODS： To create digitized visible model of the FSDP and related structures with the coronal CT data sets of a patient by AutoCAD （computer aided design）, MOI （Moment of Inspiration） and SketchUp software package. The spatial relationship of the FSDP and related structures in the 0°rod-lens telescope with the 60° elevation angle （between the endoscope and bottom of nasal cavity） was simulated and observed. The images from the coronal CT were compared with the images of CT in the endoscope. The operation of the endoscope surgery was simulated. RESULTS AND CONCLUSION： The digitized visible model of the FSDP and related structures for the endoscopic surgery was successfully reconstructed. The changes of visual spatial orientation were consistent with the perspective law. The drainage pathway and the spatial relationship of frontal sinus with related structures could be observed. The simulation of the endoscopic surgical process of the FSDP and related structures may be used for establishing the right visuospatial relationship. There were differences in the image of two dimensions, the solid of three dimensions and the visual field of the endoscope, which validated the perspective law in the visual space of the endoscope. The visuospatial concept of the endoscope was brought and emphasized. Digitized visible model provides the means to learn the endoscopic anatomy of the FSDP and can be used as teaching and simulating tool of surgical techniques.