Study On The Visualization Of Tissue Damage Degree In HIFU Treatment Based On Pseudo-Color Technology

High intensity focused ultrasound(HIFU) has become a brand new noninvasive method for the treatment of tumor following the surgery, radiotherapy and chemotherapy. Real-time monitoring from beginning to the end and objective tissue damage degree evaluation method are the key to ensure the effect of HIFU treatment and the surrounding normal tissue not be damaged. At the same time, it’s also the focus of the scholars’ studies. At present, damage degree of the organization in HIFU focus area is mainly judged by the doctor’s experience according to the B-mode ultrasound real-time monitoring image, lacking of objectivity and scientific nature.To achieve the visualization of the tissue damage degree in HIFU treatment, the gray-color transformation method is modified and a pseudo-color encoding method based on the correlation coefficient of the HIFU monitoring image is proposed in this paper. The main work is as follows:(1) The pretreatment of the image. Including the B-mode ultrasonic monitoring images obtained before and after HIFU radiation format transformed, registration, cut and normalized. These can improve the efficiency of the pseudo-color coding or reduce the error produced by image dislocation and the gray level difference which have no medical significance.(2) Improved the Gray-color transform method. To enhance the organization’s damage area, this paper incorporates the difference image between the image before irradiation and the image after irradiation which contains the tissue damage information and the image after irradiation. According to the characteristics of the ultrasound monitoring image, using the K-means clustering algorithm to set the threshold of transform function. Experiments show that the damage information of the images got by this method are more clearly and the color of the images are richer.(3) Put forward a pseudo-color encoding method based on the correlation coefficient of the HIFU monitoring image. Firstly, extract the correlation coefficient matrix which contains the tissue damage information. Then the correlation coefficient matrix is mapped to H component of the HSI color space. At the same time, the color perception theory is applied to the Pseudo-color coding. Compared with traditional pseudo-color encoding methods, the color of the pseudo-color images obtained by this method are more accord with people’s visual habit, ties closer with tissue damage information, and the tissue damage information in HIFU focus area are richer.Focusing on the application of Pseudo-color processing technology in the visualization of tissue damage degree during the HIFU treatment, this paper has done a lot of research and exploration. These can provide a lot of intuitive and reliable information for HIFU equipment operators, which is very important to promoting the follow-up development and clinical application of HIFU technology.