A focal positioning method used in the MR-guided focused ultrasound surgery system

MR-guided focused ultrasound surgery is a promising noninvasive thermotherapy. To achieve a rapider and more accurate treatment requires continuous attention. In this paper, a more precise method for focal positioning is proposed. The ultrasound transducer with phased array can shift the focal position within the target area. Several points with appropriate distance are selected to establish the mapping between ultrasound coordinates and MR coordinates. Then the target spots in a certain region can be aimed precisely. According to the experiment result, the error is limited to less than 1mm.