HIGH-INTENSITY FOCUSED ULTRASOUND FOR HEATING A TARGET ZONE LARGER THAN THE ELECTRONIC FOCUSING ZONE

摘要

The invention provides for a medical instrument (200) comprising a magnetic resonance imaging system (202) and a high-intensity focused ultrasound system (204) with an electronically controllable and a mechanically controllable focus. Execution of instructions by a processor (244) controlling the instrument cause the processor to: receive (100) a target zone (240, 264) descriptive of a zone within the subject; divide (102) the target zone into multiple sub-zones (416, 418, 420, 422, 424, 426, 428, 430, 432, 434); determine (104) a sequence (272) for moving the transducer position to each of the multiple sub-zones; determine (106) a selected sub-zone selected from the multiple sub-zones using the sequence; repeatedly control (108) the mechanical positioning system to move the transducer to the transducer position of the selected sub-zone; repeatedly acquire (110) the magnetic resonance thermometry data; repeatedly determine (112) a temperature property map (274); repeatedly heat (114) the regions independently to the target temperature by controlling the electronically controlled focus with a temperature feedback algorithm (286); and repeatedly change (116) the selected sub-zone using the sequence.