A Comparison Of Ultrasound-based QA And Ln(D)U Methods For Measurement Of Local Pulse Wave Velocity

In recent years,cardiovascular disease has become one of the largest threats to human health,and its major pathological basis is atherosclerosis.As an independent predictor of cardiovascular events,pulse wave velocity(PWV)can quantitatively reflect the degree of arteriosclerosis.Due to the significant differences in elasticity at various sites along the arterial tree,it’s important to timely understand the elastic changes of local blood vessels for the early precaution and diagnosis of cardiovascular diseases such as arteriosclerosis.As the main method of arterial local PWV detection,ultrasonic detection technology is characterized by simple operation,convenience,non-invasive,repeatability and good real-time performance.The ultrasound system is used to simultaneously detect the pulsating changes of the lumen diameter(D)and central blood flow velocity(U)using the ln(D)U method and QA method are the current research focus of estimating arterial local PWV.But in the former model-based studies,the QA method conflicted with the ln(D)U method,and the flexibility and extensiveness in setting model parameters are restricted due to the limitation of the modeling materials in the study of the physical mode.Therefore,there is currently no comprehensive systematic comparative study on the difference in detection accuracy between the QA method and the ln(D)U method.To this end 5 in this paper we compare the accuracy difference between QA and ln(D)U methods in detecting PWV by establishing the computer ultrasonic simulation blood vessel pulsatile model and clinical carotid artery in vivo test.Firstly,the SonixTouch RP ultrasound system is used to detect the blood velocity and lumen radius pulsating curves of the human’s left carotid artery as the simulated theoretical curves.And established the computer simulation model of carotid artery.Based on this,the PWVs are estimated based on the QA method and the ln(D)U method,respectively.The detection accuracy of the two methods is quantitatively compared with the theoretical preset values.In clinical trials,20 subjects in two age groups are tested for vascular and blood flow ultrasound RF echo signals of 10 cardiac cycles in the left carotid artery,and radius and blood velocity pulsated curves are extracted according to Echo tracking technique and Pulse Wave Doppler technique.Then estimated the actual PWVQA and PWVln(D)u.The repeatability and correlation performance of QA method and the ln(D)U method are compared qualitatively and quantitatively by plot the Bland&Altman diagrams,and calculating the coefficient of variations(CV).The experimental results of 30 groups based on the simulation models show that the normalized root-mean-square-errors of local PWV estimated by QA method and ln(D)U method are 0.30±0.08 and 0.45 ± 0.13,respectively.The results of 20 subjects in two age groups show that there is a strong correlation between the PWVs detected by QA and ln(D)U methods,and the correlation coefficient is 0.94.The estimated coefficients of variation based on these two methods are 12.08%and 13.17%,respectively.The results of computer simulation and clinical in vivo experiments show that the performance of QA method for detecting arterial local PWV is better than that of ln(D)U method.