标题: | 利用以影像细胞单元元素为主的二元主动寻找轮廓模型侦测超音波影像中的肿瘤边界 A Cell-Based Dual Snake Model for Lesion Boundary Detection in Ultrasound Images |
作者: | 黄咏祥 Yueng-Shiang Huang 卢鸿兴 Dr. Horng -Shing Lu 统计学研究所 |
关键字: | 主动寻找轮廓模型;二元主动寻找轮廓模型;分水岭转换;多重解析高斯平滑化;以影像细胞单元为主;snake model;dual snake;watershed transform;multi-scale gaussian smoother;cell-based |
公开日期: | 2000 |
摘要: | 超音波影像由于其无侵害性,即时,方便以及便宜的优点已经成为现代医学在初期的临床诊断上一项非常重要的工具。但是也因为超音波影像具有高杂讯的特性,使得传统上以像素为主(pixel-based)的主动寻找轮廓方法(snake model)在这里并不适用。在这里我们提出一种以影像细胞单元元素为主(cell-based)的二元主动寻找轮廓模型方法去对超音波影像进行影像分割。这种以影像细胞单元为主的方式可以解决一般主动寻找轮廓模型在局部极小值方面的缺点。我们利用多重解析(multi-scale)的高斯平滑化去对影像进行去除杂讯且可保留影像边界的平滑,并利用分水岭转换去得到初始的影像细胞单元元素的资讯。根据影像细胞单元的概念,我们除了要制定能量函数外,也另外去建立了一种新的形变过程。另外,二元主动寻找轮廓中的内部与外部轮廓彼此之间也会提供一个拉扯的力去避免两者之中任何一个被局部极小值所造成的陷阱牵制的缺点。最后,我们将会以电脑模拟的影像去验证我们的结果,并实际应用在超音波影像的影像分割上。 Ultrasound imaging is an important diagnosis tool for early detection and regular check-ups because of its non-invasion, real-time, convenience and economy. Owing to the low signal-to-noise ratio in ultrasound images with speckle noises, it is difficult to segment with classical active contour methods, like the snake-balloon model. This study will propose a cell-based dual snake model to segment ultrasound images. The classical pixel-based snake model and its modifications are easily trapped at local minima and we propose cell-based approach to solve this problem. Initial cells contains the capture ranges near high measures of edges are produced by the multi-scale Guassian smoothing filters and watershed transform. The energy function is established based on the original intensities of cells and the movements of the active contour will be generated upon it. Dual snakes of inner and outer contours based on cells are also used to provide additional pull forces when one of them is trapped at local minima. This new approach will be tested on simulated and clinical ultrasound images and the performance is reported in this study. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT890337015 http://hdl.handle.net/11536/66766 |
显示于类别: | Thesis |