Research On 3D Reconstruction And Quantitative Analysis Of Coronary Arterial Tree Based On Angiograms

Coronary angiography is regarded as the "gold standard" for the assessment of coronary artery disease. We are now carrying out a research project supported by the Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) under the contract no. 20030056018. The project is entitled "2D extraction and 3D reconstruction of vessel net based on the angiograms". The core of this dissertation is 3D reconstruction of coronary arterial tree and the 3D quantitative analysis of vessel. The main contents of this dissertation include seven parts as follows: 1. Theoretical Model of 3D reconstruction We construct the simplified model of angiographic system according to its moving characters, and describe the transformation between the two angiograms using a rotation matrix and a translation vector. In addition, we present two methods to calculate 3D coordinate, which are Least Square Solution and Geometric Solution. 2. Segmentation of 2D tree and vessel-matching After segmentation of 2D skeleton tree, we use Directed Graph, Directed Tree and Binary Tree to describe the topological structure of arterial tree. At the same time, Node Weight and Similar Node are defined, by which the vessels are matched successfully. 3. Optimization of transformation Bifurcations, vessel vectors and branch angles are used to optimize the geometric transformation which is expressed as seven variables. 4. 3D reconstruction of coronary arterial tree's skeleton We propose a new method based on B-spline for reconstructing 3D skeleton. It mainly includes 2D B-spline curve fitting and optimization of 3D B-spline control points. 5. 3D reconstruction of vessel surface On the assumption that vessel is generalized column, we establish the elliptical model of vessel's cross-section and present vertex-merging method to solve the problem of neighboring cross-sections' intersection. In addition, three methods are studied for 3D reconstruction of vessel surface, including Sphere Envelope, Triangularization and NURBS Surface Fitting. 6. Experiment of 3D reconstruction The computer-simulated images, clinical angiograms and vessel phantom's angiograms are respectively used for the experiment of 3D reconstruction. The performance of the method is validated by the statistic of reconstruction errors. 7. 3D quantitative analysis of coronary artery On the basis of 3D reconstruction, we study the 3D quantitative analysis of vessel, and propose a method to calculate the 3D values of diameter, length, and volume and branch angle. The method is validated by 3D quantitative analysis of vessel phantom.