Abstract: A magnetic-resonance-guided focused ultrasound system may be calibrated by generating ultrasound foci using ultrasound transducers, establishing coordinates of the foci and of magnetic-resonance trackers associated with the transducers, and determining a geometric relationship between the trackers and the transducers.

Abstract: Techniques for temperature measurement and correction in long-term MR thermometry utilize a known temperature distribution in an MR imaging area as a baseline for absolute temperature measurement. Phase shifts that arise from magnetic field drifts are detected in one or more portions of the MR imaging area, facilitating correction of temperature measurements in an area of interest.

Abstract: A method for treating body tissue using acoustic energy includes identifying a target focal zone of tissue to be treated, delivering a first pulse of acoustic energy from a transducer to generate bubbles in a tissue region located distally, relative to the transducer, of a focal center of the target focal zone, and delivering a second pulse of acoustic energy from the transducer in the presence of the bubbles generated by the first pulse, the second pulse focused at the focal center to generate thermal ablation energy. In a further embodiment, a method of treating body tissue using ultrasound energy includes identifying a target focal zone to be treated and delivering a plurality of pulses of acoustic ablation energy to locations distributed symmetrically in or proximate a focal plane about the focal center of the target focal zone.

Abstract: Techniques for temperature measurement and correction in long-term MR thermometry utilize a known temperature distribution in an MR imaging area as a baseline for absolute temperature measurement. Phase shifts that arise from magnetic field drifts are detected in one or more portions of the MR imaging area, facilitating correction of temperature measurements in an area of interest.

Abstract: A magnetic-resonance-guided focused ultrasound system may be calibrated by generating ultrasound foci using ultrasound transducers, establishing coordinates of the foci and of magnetic-resonance trackers associated with the transducers, and determining a geometric relationship between the trackers and the transducers.

Abstract: Ultrasound energy is delivered to a patient in a controlled manner using a focused ultrasound system, thus maintaining the desired therapeutic effect without causing unwanted damage to surrounding tissue. An ultrasound transducer device includes multiple transducer elements, each of which is controlled by drive circuitry and a drive signal controller. An acoustic detector detects signals indicative of cavitation in tissue targeted by the transducer elements, and the drive signal controller manages the delivery of acoustic energy from the transducer elements based on the detected cavitation signals such that a therapeutic effect at the target tissue remains within an efficacy range.

Abstract: A method for treating body tissue using acoustic energy includes identifying a target focal zone of tissue to be treated, delivering a first pulse of acoustic energy from a transducer to generate bubbles in a tissue region located distally, relative to the transducer, of a focal center of the target focal zone, and delivering a second pulse of acoustic energy from the transducer in the presence of the bubbles generated by the first pulse, the second pulse focused at the focal center to generate thermal ablation energy. In a further embodiment, a method of treating body tissue using ultrasound energy includes identifying a target focal zone to be treated and delivering a plurality of pulses of acoustic ablation energy to locations distributed symmetrically in or proximate a focal plane about the focal center of the target focal zone.