膀胱三维几何及特征映射模型研究

发布时间：2018-06-25 22:18

本文选题：膀胱 + 几何模型　；参考：《西北大学》2014年硕士论文

【摘要】：膀胱肿瘤是男性第四大易发肿瘤,具有致死率、复发率高等特点,早诊断早治疗是防治关键。虚拟内窥镜技术是一种无创、无痛、前景可观的管腔内部肿瘤检查方法,近年来在体检中被广泛采用。基于虚拟内窥镜的膀胱肿瘤计算机辅助检测技术,主要包括膀胱器官三维重建,表面肿瘤形态、纹理描述及建模等,可为医生提供更加直观的检测和诊断参考。本文研究了基于曲面参数膀胱器官的几何和纹理建模方法,具体内容有： (1)提出了一种半自动的膀胱壁分割算法——基于层间扩散的Snake算法,该方法可以有效的将膀胱壁从MRI数据中分割出来。 (2)提出了一种面向点云的表面重建算法,利用自由变形技术将初始的参数模型迭代拟合至膀胱点云轮廓,生成膀胱的参数变形模型,即膀胱几何模型。由于膀胱模型是参数变形模型,所以很容易对其渲染可视化显示、量化比较及快速检索等。 (3)提出了基于参数变形模型的特征投影技术,将点云的表面特征(厚度特征、纹理特征等)映射至参数模型表面,形成二维特征映射模型有利于计算机辅助肿瘤的快速检测。 (4)提出了膀胱的归一化模型。将任意膀胱器官映射至标准化圆球球形模型上,为膀胱提供了统一的表达和量化比较方法。理论推导和实验均表明,本文提出的模型可以描述了膀胱的整体形状,更有表面局部细节特征的描述能力,为医生提供了可度量和更加深入的可视化方法,也为后期的计算机辅助检测提供了更好的基础。
[Abstract]:Bladder tumor is the fourth most prone tumor in men, with the characteristics of mortality and high recurrence rate. Early diagnosis and treatment is the key to prevention and treatment. Virtual endoscopy is a noninvasive painless and promising method for the examination of intraluminal neoplasms which has been widely used in medical examination in recent years. The computer-aided detection technology of bladder tumor based on virtual endoscope, which mainly includes three-dimensional reconstruction of bladder organ, shape of surface tumor, texture description and modeling, can provide more intuitionistic detection and diagnosis reference for doctors. In this paper, geometric and texture modeling methods of bladder organs based on curved surface parameters are studied. The main contents are as follows: (1) A semi-automatic bladder wall segmentation algorithm, Snake algorithm based on interlayer diffusion, is proposed. This method can effectively segment the bladder wall from MRI data. (2) A point cloud oriented surface reconstruction algorithm is proposed. The initial parameter model is iteratively fitted to the point cloud profile by free deformation technique. The parametric deformation model of the bladder is generated, that is, the geometric model of the bladder. Because bladder model is parametric deformation model, it is easy to render visual display, quantitative comparison and fast retrieval. (3) feature projection technology based on parameter deformation model is proposed. The surface features (thickness feature, texture feature, etc.) of the point cloud are mapped to the surface of the parameter model to form a two-dimensional feature mapping model. (4) A normalized model of bladder is proposed. By mapping any bladder organ to a standardized spherical sphere model, a unified expression and quantitative comparison method is provided for the bladder. Both theoretical and experimental results show that the proposed model can describe the global shape of the bladder, have the ability to describe the local details of the surface, and provide a measurable and more in-depth visualization method for doctors. It also provides a better basis for later computer aided detection.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP391.41;R737.14

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