A medical apparatus (300, 400, 500), comprising: - a high intensity focused ultrasound system configured for generating focused ultrasonic energy for sonicating a target volume of a subject; - a magnetic resonance imaging system for acquiring magnetic resonance data (356, 358, 360, 368, 374) from an imaging zone, comprising the treatment volume; - a memory containing machine executable instructions for controlling the medical apparatus; - a control module (382, 402) for controlling the sonication of the target volume using the magnetic resonance data as a control parameter; - a processor for controlling the medical apparatus, wherein execution of the instructions causes the processor to repeatedly: - acquire (102, 202) magnetic resonance data in real time using the magnetic resonance imaging system; and - control (104, 206) sonication of the target volume by the high intensity focused ultrasound system in real time using the sonication control module and the magnetic resonance data, - wherein the magnetic resonance data comprises subsampled magnetic resonance data and image magnetic resonance data, wherein the medical apparatus further comprises an image reconstruction module for reconstructing the image magnetic resonance data into a magnetic resonance image, where the sonication control module is configured for using at least the subsampled magnetic resonance data as the control parameter, and wherein execution of the instructions further causes the processor to repeatedly reconstruct an image using the image reconstruction module and the image magnetic resonance data, and wherein the magnetic resonance imaging system is configured to acquire the subsampled magnetic resonance data and image magnetic resonance data in an interleaved fashion. - a high intensity focused ultrasound system configured for generating focused ultrasonic energy for sonicating a target volume of a subject; - a magnetic resonance imaging system for acquiring magnetic resonance data (356, 358, 360, 368, 374) from an imaging zone, comprising the treatment volume; - a memory containing machine executable instructions for controlling the medical apparatus; - a control module (382, 402) for controlling the sonication of the target volume using the magnetic resonance data as a control parameter; - a processor for controlling the medical apparatus, wherein execution of the instructions causes the processor to repeatedly: - acquire (102, 202) magnetic resonance data in real time using the magnetic resonance imaging system; and - control (104, 206) sonication of the target volume by the high intensity focused ultrasound system in real time using the sonication control module and the magnetic resonance data, - wherein the magnetic resonance data comprises subsampled magnetic resonance data and image magnetic resonance data, wherein the medical apparatus further comprises an image reconstruction module for reconstructing the image magnetic resonance data into a magnetic resonance image, where the sonication control module is configured for using at least the subsampled magnetic resonance data as the control parameter, and wherein execution of the instructions further causes the processor to repeatedly reconstruct an image using the image reconstruction module and the image magnetic resonance data, and wherein the magnetic resonance imaging system is configured to acquire the subsampled magnetic resonance data and image magnetic resonance data in an interleaved fashion. - acquire (102, 202) magnetic resonance data in real time using the magnetic resonance imaging system; and - control (104, 206) sonication of the target volume by the high intensity focused ultrasound system in real time using the sonication control module and the magnetic resonance data, - wherein the magnetic resonance data comprises subsampled magnetic resonance data and image magnetic resonance data, wherein the medical apparatus further comprises an image reconstruction module for reconstructing the image magnetic resonance data into a magnetic resonance image, where the sonication control module is configured for using at least the subsampled magnetic resonance data as the control parameter, and wherein execution of the instructions further causes the processor to repeatedly reconstruct an image using the image reconstruction module and the image magnetic resonance data, and wherein the magnetic resonance imaging system is configured to acquire the subsampled magnetic resonance data and image magnetic resonance data in an interleaved fashion.