Finite Element-Based Ultrasound Images Analysis

Motion analysis and its application are main branch of computer vision, which are related to most of computer vision study. Furthermore, Optical-flow field motion is very important for computer vision study, which investigates lightness pattern of images changing with time and formation motion field. In other words, the motion of object results in images formation. In this thesis we focus on ultrasound cardiac images study by optical-field displaying the motion of sequence images.It is well known that heart is a vital organ in human body. Considering the fact that heart's function is closely related to its motion pattern, a lot of attentions have been paid to its kinetics information in the structure diagnosis of heart diseases. With the quick development of modern medical image formation technique, it can provide doctors with global information of cardiac structure. This thesis carries out a study on motion quantitative analysis, mainly on cardiac sequence ultrasound images with motion analysis technique of computer vision. Three main parts of the study of this thesis are as follows.Firstly, we have learned some algorithms about motion analysis, and then had some experiments including Horn algorithm, moment based methods and blocks based motion model and so on. Secondly, Aiming at the small displacement and the strong gray and position correlation between the two neighboring sequence images, we have presented a correlative algorithm of 2-D optical-flow field for cardiac sequence image. In order to test the feasibility of correlative algorithm, we have performed a quantitative analysis in a serial of simulative sequence images, and the experimental results demonstrate the effectiveness of the method. Thirdly, A medical image composed of pixels is taken as continuous and compact elastic plane sheet, so according to the theory of elastic force, we may change the elastic motion analysis of images to transfiguration of elastic object. Assuming that linear elastic continuums will deform following the elastic rules of Hook and taking the transformation of linear elastic organs in medical images as that of continuity, Finite element method is used to perform motion analysis, which is non-rigid algorithm based motion. We have introduced the theory of finite element method, made element grid, synthesized element and the results are shown and compared.