基于MSCT的感兴趣血管段CAG最佳视角和冠脉运动估计的研究

发布时间：2018-08-02 11:28

【摘要】：冠心病是威胁中国公众健康的重要疾病,目前临床普遍采用的影像学诊断方式是X射线冠状动脉造影(coronary angiography,CAG)和多层螺旋计算机层析成像(multislice computed tomography,MSCT)。CAG被称为诊断冠心病的“金标准”,但其本质为透视投影成像,若造影角度选择不当,容易引起血管投影缩短和血管相互间遮盖,影响感兴趣狭窄血管段的诊断与治疗,因此确定感兴趣段的最佳造影角度具有重要的意义。 MSCT技术近年来得到了迅速发展,以无创成像、三维容积数据等优势在冠心病排查及术前分析中应用越来越广泛。本文的主要研究目的是采用计算机视觉和数字图像处理方法,对术前MSCT心脏数据进行分析,分割三维冠脉血管,同时建立CAG系统几何模型,研究介入手术中感兴趣血管段最佳造影角度的计算方法,并对多期相的冠脉进行运动分析,辅助诊断冠心病。本文的研究内容主要包括: 一.建立系统整体数据处理方案根据X射线冠脉造影与多层螺旋CT两种冠脉成像技术的特点及相关技术参数,提出了基于多层螺旋CT数据的术前分析方案,进行感兴趣血管段最佳造影角度确定及冠脉运动分析,建立了课题的整体数据处理流程。二.多层螺旋CT数据中的冠脉分割选择区域生长机制,同时辅以必要的预处理步骤,分别与概率决策、基于Hessian矩阵的血管增强滤波及基于最佳方向性梯度通量的血管增强滤波结合,以获得满意的分割效果。三.基于多层螺旋CT血管模型的最佳造影角度计算建立由CT数据坐标系到造影系统坐标系的几何变换模型,模拟二维投影图像。对感兴趣段血管进行基于形态学的细化,并进行B样条拟合,同时满足最小投影缩短和最小遮盖的角度,即为造影系统的最佳视角。四.基于多层螺旋CT数据的冠脉运动初步分析对多期相的骨架点进行基于连贯点漂移的非刚体配准,实现运动场估计,定量描述主要分支的位移幅度与速率。利用全期相冠脉数据,建立动态血管模型,计算了整个心动周期内的冠脉最佳造影角度。
[Abstract]:Coronary heart disease (CHD) is an important disease threatening the public health in China. At present, X-ray coronary angiography (coronary) and multislice spiral computed tomography (multislice computed tomographic MSCT) .CAG are commonly used in clinic as the "golden standard" for the diagnosis of coronary heart disease. However, its essence is fluoroscopic projection imaging. If the angle of angiography is not properly chosen, it will easily lead to the shortening of vascular projection and the mutual covering of blood vessels, which will affect the diagnosis and treatment of stenosis of interest. Therefore, it is of great significance to determine the optimal imaging angle of the segment of interest. In recent years, MSCT technology has been developed rapidly. The advantages of non-invasive imaging and three-dimensional volumetric data are more and more widely used in coronary heart disease examination and preoperative analysis. The main purpose of this paper is to use computer vision and digital image processing to analyze the preoperative MSCT cardiac data, to segment the three-dimensional coronary artery, and to establish the geometric model of CAG system. To study the method of calculating the optimal angle of coronary artery segment in interventional surgery and to analyze the motion of multi-phase coronary artery in order to help diagnose coronary heart disease. The main contents of this paper are as follows: 1. According to the characteristics of X-ray coronary angiography and multi-slice spiral CT and the related technical parameters, a scheme of preoperative analysis based on multi-slice spiral CT data was proposed. The optimal angle of angiography and coronary artery motion analysis were determined and the whole data processing process was established. II. The growth mechanism of coronary artery segmentation in multi-slice spiral CT data is selected, and the necessary preprocessing steps are used, respectively, and the probability decision is obtained. The combination of the Hessian matrix based vascular enhancement filter and the optimal directional gradient flux is used to obtain a satisfactory segmentation effect. Three Based on the optimal angiographic angle of multi-slice spiral CT angiography model, a geometric transformation model from CT data coordinate system to imaging system coordinate system is established to simulate two-dimensional projection image. The vessels of interest are refined based on morphology and fitted with B-spline, which satisfies the angle of minimum projection shortening and minimum shading, that is, the best angle of view of the imaging system. four Preliminary Analysis of Coronary artery Motion based on Multi-slice Spiral CT data the nonrigid body registration of multi-phase skeleton points based on coherent point drift is carried out to estimate the motion field and quantitatively describe the displacement amplitude and velocity of the main branches. Based on the whole phase coronary artery data, a dynamic vascular model was established, and the optimal angle of coronary angiography was calculated for the whole cardiac cycle.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R816.2

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