Ultrasonic Imaging Method And Experiment Of Left Ventricular Vortexes And Wall Motions

At present,the increasing burden of cardiovascular disease has become a major public health problem.The incidence of cardiovascular disease is often associated with abnormal of cardiac blood flow patterns,the changes or disorders of the blood flow dynamics may lead to cardiac dysfunction and various cardiovascular diseases.Vortex is a major determinant of the cardiac blood flow,and it is a good indicator for cardiac performance.Ventricular abnormal wall motion may lead to changes in cardiac morphology,cardiac deformation indicates cardiac pathology,which is closely related to the prognosis of heart disease.Ultrasonography is widely used in examination of human body tissues,because in terms of advantage such that real-time,noninvasive,low cost,and no restrictions on transplantation equipment in vivo.The purpose of this paper is combined with vortex and wall motion evaluation of left ventricular function,the main goal of this paper is to study whether the combined parameters of vortex and elastic wall motion can be used as a basis for quantitative assessment of left ventricular function,parameters including kinetic energy fluctuations indices,relative strengths,and energy dissipation index of vortex and wall displacement of wall.This method based on the two aspects is called biomechanics algorithm,it improves the accuracy of the algorithm by adding sub-pixel method,median filtering and linear interpolation,elimination and correction of the pseudo vector and multiple iterations in cross-correlation algorithm.In vitro study,imaging of phantoms with different elastic modulus were acquired by simulation experiments,the velocity vector distribution of blood flow and displacement distribution of wall motion were calculated by the algorithm.On the one hand,vorticity distribution and wall shear stress distribution were deduced by the velocity vector distribution.It was found that there was a peak value of vorticity or wall shear stress at the center of vortex,and the peak value tended toward increase with increasing of the elastic modulus.Four parameter of vortex were computed,and it was found that there was significant difference between the three values with Young's modulus.On the other hand,the cumulative displacement curve could be deduced by calculating the displacement of segmental motion,it was found the displacement peak value decreased with the increasing of the elastic modulus.In vivo study,these parameters and additional strain were also calculated.According to the results in vivo study,it was speculated that the patients with heart disease had a larger absolute value in vorticity,and a smaller displacement value compared with the normal.So conclusions in vivo studies are basically consistent with those in vivo.The study in both vortex and wall motion provide clinical prognosis basis.