POWER ADJUSTMENT IN MAGNETIC RESONANCE GUIDED HIGH INTENSITY FOCUSED ULTRASOUND

摘要

The invention provides for a medical instrument (100) comprising: a magnetic resonance imaging system (102) and a high intensity focused ultrasound system (122) comprising an ultrasonic transducer (126). The ultrasonic transducer being configured for simultaneously heating multiple sonication volumes (138, 138', 138''). Execution of machine executable instructions (180) cause a processor (174) to: receive (300) sonication commands (188) configured for controlling the ultrasonic transducer to sonicate the multiple sonication volumes, receive (302) an acoustic power setting (190) for scaling the acoustic power, wherein the relative power of the electrical voltage supplied to each of the multiple ultrasonic transducer elements is scaled using the acoustic power setting, and control (304) the high intensity focused ultrasound system to sonicate the multiple sonication volumes. During the sonication, the processor repeatedly: acquires (306), and reconstructs (308), and displays 310) a thermal map (194) of the multiple sonication volumes. During the sonication, the processor further repeatedly: receives (312) a pause command (196) which causes the processor to pause the sonication of the multiple sonication volumes; receives (314) a resume command (196) which causes the processor to resume the sonication of the multiple sonication volumes; and receives (316) a change power command which causes the processor to change (320) the relative power of the electrical voltage supplied to each of the multiple ultrasonic transducer elements proportionally by a value specified in the change power command, wherein an increase of the relative power of the electrical voltage supplied to the ultrasonic transducer above a predetermined value (198) is only performed if (318) the sonication of the multiple sonication volumes is paused.