Research On Three-Dimensional Speckle Tracking Echocardiography And Its Applications

Three-dimensional speckle tracking imaging technology is a new technology that it is developed based on speckle tracking and dynamic three-dimensional echocardiogram.The technique can obtain the myocardial motion parameters such as trajectory,displacement,velocity,and assess of myocardial function such as strain,strain rate,twist by tracking three-dimensional speckles accurately in three-dimensional echocardiogram.It can be significant for quantitative analysis of the myocardial function.Two-dimensional speckle tracking imaging technology,which has been successfully applied in clinical,does not utilize Doppler information and is not affected by the incident angle of the ultrasonic wave.It can obtain the movement characteristics of myocardium by tracking speckles in echocardiogram.The heart is a three-dimensional structure,and the movement is extremely complex.Two-dimensional speckle tracking imaging technology is limited to two-dimensional plane,when the speckles move beyond the two-dimensional image,the tracking effect can be affected.Three-dimensional speckle tracking imaging technology is carried out in three-dimensional without the loss of speckles,and improve accuracy of tracking.In addition,Three-dimensional speckle tracking imaging technology can also track all segments of the myocardium while analyzing the segmental motion of the myocardium.It can reduce computational effort and improve efficiency of tracking,and assess left ventricular myocardial function faster and more accurately.The speckle is formed by the interference of the scattering echo generated by the propagation of ultrasound in tissue and blood.Speckle is randomly distributed have the uniqueness and stability,and speckle movement law can reflect the movement of myocardial tissue in the region.This paper proposes a three-dimensional speckle tracking method based on improved diamond search(IDS)algorithm.Firstly,three criteria determining the performance of 3D block matching speckle tracking is analyzed.Secondly,this paper studies and analyzes theoretically all kinds of classical search algorithms,and proposes an improved diamond search algorithm based on adaptive search step.The algorithm can predict the search step by the motion vector of the adjacent block that has completed the search with the spatial correlation of the image motion.Simulation of all kinds of algorithms is carried out,and the paper analyzes objectively property of all kinds of algorithms with the quantitative evaluation index.The paper demonstrates the theoretical feasibility of three-dimensional speckle tracking method based on improved diamond search algorithm by STRAUS data set of the simulation of three-dimensional echocardiogram,and compared with the three-dimensional speckle tracking based on traditional diamond search algorithm.Coronary heart disease is a serious threat to human health,and is the main cause of human death,early diagnosis and treatment timely can help to recuperate human health quickly.The biomechanical characteristics of myocardial tissue is an important indicator of the diagnosis of disease.Calculation method of three-dimensional radial strain based on echocardiographic three-dimensional speckle tracking is proposed and is realized autonomously.The reliability of the method is verified by STRAUS data set.And the method is compared with two-dimensional radial strain analysis,the proposed method can reflect elastic deformation of myocardial tissue better.