The Ultrasound Simulation Of Carotid Artery Plaque And System Implementation

In recent years,the carotid atherosclerosis has become one of the high rate of diseases which threaten people's health seriously.Carotid atherosclerosis is the most common and serious vascular disease,it has low cure rate and high recurrence rate.Therefore,the identification and diagnosis of this disease in time is very important to prevent it from deteriorating and decrease incidence rate and mortality.Among the methods of detecting the atherosclerosis,ultrasound is the most widely used method because of its advantages of non-invasive,real-time,convenient and so on.But in clinical operation,the inherent noise in ultrasound images,artifact,the skills and experience of the operator and so on will influence the accuracy of the diagnosis.So how to use the method of computer ultrasound simulation to train diagnostic clinicians and improve the accuracy of diagnosis has become a research hotspot.There are many ultrasound simulation methods,but these methods lack the comprehensively and systematically description of plaque's geometrical features and tissue features.This paper summarizes the geometrical features and tissue features of plaque based on analyzing the clinical dates.Then the three-dimensional model and tissue model were established according to the features of plaque.A method of using tubular and multiple branches tissues modeling based on the metaball to describe the three-dimensional model of carotid artery plaque is proposed.The tissue scatterer model with the position of a Gamma distribution is adopted.The relationships between the parameters such as shape and density of the tissue scatterer distributions and the ultrasonic echo speckle distributions are investigated.Then the Field II software is used to calculate the RF echo signals and generate various types of B-Mode ultrasound images of the carotid artery plaques based on envelope extraction,interpolation and logarithm compression.In addition,the carotid artery ultrasonic simulation system is designed and developed by using the Matlab GUI.The system can make the operations personnel choose the species,shapes and tissue characteristics of plaque freely,and it fully display the geometric construction,tissue size and distribution characteristic,so this system provide the objective data source and evaluation basis for study of the feature extraction method of plaque.Finally,quantitative and qualitative analysis of the geometry size and tissue echo spots has been made by dividing the simulation results and clinic images manually and elaborately.The results show that the simulated images can describe the tissue characters exactly,and it is coincident with the clinical features.In conclusion,simulating the carotid plaque and establishing the ultrasonic simulation system have great significance for improving the accuracy of medical worker's diagnosis and analysis of carotid artery plaque lesion.