An Extended Field-of-view Research For Medical Ultrasound Elastography

Through the continuous development,medical ultrasound imaging technology,one of the most important medical imaging techniques,has been widely used in clinical diagnosis with its various advantages.The advantages of ultrasound imaging are as follows: good instantaneity,non-invasive,convenient and no ionizing radiation.Ultrasound elastography images by getting elasticity information of the tissue,it makes up the deficiency that traditional ultrasound imaging cannot provide the information of tissue stiffness and becomes an adjunct in the diagnosis of disease.Therefore,it has become a hot issue in the research of medical ultrasound imaging.The field of view of ultrasound elastography is limited by the probe width.To solve this problem,3-dimensional(3D)ultrasound elastography is commonly used,which time complexity is relatively high.Ultrasound extended field-of-view(EFOV)makes it possible to construct a panoramic view,while the panoramic image is generated from 2-dimensional(2D)B-mode ultrasound images or 3D ones.This paper is focused on an EFOV research for medical ultrasound elastography.This paper firstly introduces the basic principle of ultrasonic elastography,analyzes the steps of EFOV emphatically,including image acquisition,image registration and image fusion.Freehand scanning method is used to acquire radio frequency(RF)signal frame sequences and B-mode ultrasound images,then a displacement estimation algorithm based on dynamic programming is selected for ultrasound elastography of this paper.In this paper,we propose an improved EFOV method based on the position information of each image acquired.Also we apply the method to diagnose scoliosis which relies on the measurement of radian and some experiments are conducted.The EFOV image for ultrasound elastography is finally generated by a series of continuous space areas and the image corresponding to each area which are calculated by the ultrasound images and the corresponding position datas.Experiments have been conducted to test the accuracy of the method we proposed.Ultrasound phantom experiment results show that accurate EFOV elastography images can be generated,human forearm experiment results demonstrate the distribution of tissue strain information accurately in a large range.