Research On Key Technology Of Ultrasound Imaging Simulation

Medical ultrasound imaging diagnosis as a professional diagnostic method requires a large number of case data on the ultrasound equipment operator's professional pre-job training.Ultrasound imaging simulation provides an efficient and inexpensive way for ultrasound training,and can easily obtain a large number of simulated ultrasound case data,besides ultrasound imaging simulation can also be applied to the objective evaluation of ultrasound equipment design,multi-mode image Registration,image-guided surgical navigation and so on.This thesis focuses on the key technologies needed for ultrasonic imaging simulation.In this thesis,the principle of ultrasonic imaging is briefly described and explained.Ultrasound imaging is based on the basic physical principle of ultrasonic reflection,refraction,scattering and attenuation.The reflection of ultrasonic waves leads to the more obvious tissue boundary in the ultrasound image,and the scattering of the ultrasonic waves mainly forms the speckle noise in the ultrasonic image.The attenuation of the ultrasonic wave limits the detection depth of the probe,uses different ultrasonic devices to detect the human tissue,The ultrasound image is also quite different.Therefore,the key technology of ultrasonic imaging simulation includes ultrasonic probe detection model,ultrasonic reflection,speckle noise and attenuation signal calculation.The ultrasound simulation scenario is then modeled.Different probe models affect the quality of the final generated ultrasound image.In this thesis,the probe probe model is divided into single element detection and multi-array detection.CT image sequence are used to deduce the distribution of acoustic impedance in human soft tissue and establish a three-dimensional virtual data model of ultrasonic propagation.And then focus on the key algorithms of ultrasonic imaging simulation.Based on the calculation model of the reflectivity based on ray projection,the ultrasonic reflection model is divided into two types:single element detection and multi-array element.The ultrasonic beam propagation method is calculated by using the moment-based three-dimensional boundary detection operator to deduce the normal vector,improve the noise stability,and give a more accurate surface boundary parameter.In the calculation of speckle noise signal,the distribution of the scattering of the scattering particles and the construction of the point diffusion function of the scattering effect of the ultrasonic wave are studied.It is proposed to map the one-dimensional scattering particle distribution matrix into the two-dimensional image matrix using the Hilbert curve.The distribution of the scattering particles is studied and discussed by setting different probe shape parameters and scale parameters.The simulation of the ultrasonic attenuation signal is used to calculate the maximum detection range of the ultrasonic probe,and when the propagation range of the ultrasonic wave exceeds the maximum depth,the calculation of the reflectivity is stopped.Finally,the simulation results are given experimentally.In the experiment,different parameters were set up to simulate the generated ultrasound images.The simulated ultrasonic reflection,speckle noise and attenuation signal were calculated using the weighting formula,and the image quality was evaluated using the Bhattacharyya coefficient.Experiments show that the above algorithm is feasible and achieves the desired effect.