Research On Curve Tracing Technology Of Shear Waves Excited By Ultrasonic Radiation Force

In recent years,ultrasonic shear wave elasticity imaging(SWEI)is a hot spot in the development of medical ultrasound.In this paper,a real-time curve tracing method(RTCT)is proposed to overcome the shortcomings of current shear wave velocity estimation methods.The following research work has been carried out.(1)On the basis of the peak method,based on the frame rate stability and accuracy of ultrasound equipment,through image processing technology and spatial filtering,a real-time curve tracing method for shear wave velocity estimation is proposed.(2)The real-time curve tracing method is used to estimate the shear wave velocity and reconstruct the image of shear wave velocity in homogeneous region and inclusion area with elastic inclusion in standard ultrasonic phantom 040GSE.At the same time,compared with the current mainstream peak time method and peak displacement method,this method can effectively improve the accuracy of shear wave velocity estimation when the elastic value of the inclusion changes.(3)In order to verify the applicability of the real-time curve tracing method when the size of the inclusion changes,this paper makes a self-made gelatin phantom with different size inclusions and reconstructs the shear wave velocity image.By comparing with the peak method,it is concluded that the real-time curve tracing method can still reconstruct the elastic inclusion relatively completely and accurately when the inclusion size is small.(4)By changing the excitation voltage and excitation duration to change the signal-to-noise ratio,the noise adaptability experiment is completed.The experiment starts with the accuracy and relative error of shear wave speed estimation,and verifies the feasibility,accuracy and robustness of the method.The results show that the real-time curve tracing method proposed in this paper can accurately reproduce the motion trajectory of shear wave front.By fitting the shear wave curve of each frame,a more accurate two-dimensional shear wave propagation velocity estimation is achieved.Shear wave velocity estimation and shear wave image reconstruction are realized in homogeneous region and inclusion region with different clastic inclusions.Through the self-made gelatin phantom,it is verified that the method has good reconstruction quality when the diameter of the inclusion is small.Experimnental results and analysis show that the proposed shear wave velocity estimation method based on real-time curve tracing has good accuracy and robustness.In addition,the velocity reconstruction image obtained by eliminating artifacts in the shear wave transmission video can better restore the shape of the inclusion.The realtime curve tracing method can provide a new technical route for shear wave velocity estimation.