Methods To Improve The Precision Of Positioning In The MR Guided Phased Focused Ultrasound Surgery System

MR-guided PHIFU(Magnetic Resonance-Phased High Intensity Focused Ultrasound System)can realize non-invasive treatment,and it is widely used in cancer treatment.In order to use MR as the guidance,we must build a precise transfer matrix between two coordinates.This paper proposes two methods.In the first method,we can use a fully automatic image-processing algorithm to pick up points from image.In the second method,we use a new method which is based on multiple foci heating mode to get more precise positioning.At the view of automatic picking up point algorithm,we design 2 different methods.In the first shape,there are six notches around the probe,and we use Sobel edge detection algorithm to extract the probe edge.In the second shape,there are 6 pillars around the probe,and we can use K-means algorithm to select points.As for the result,the automatic picking up method is easier during operation.Moreover the result shows that automatic picking up method reduces the human errors during operation and improves the accuracy of transfer matrix.At the view of multiple foci mode method,we can get 4 foci during one cycle,and we can get 4 foci coordinates from one temperature image.Next,the article proposes a new optimal selection algorithm,which can select the optimal transfer matrix.In terms of results,it proves that multiple foci mode method could reduce errors.