A cartridge for use with an ultrasound therapy head, the ultrasound therapy head including a body with a first electrical connector, a first fluid connector, and a second fluid connector, the cartridge comprising: a sealed enclosure, the sealed enclosure configured to be removably mountable to the body, and the sealed enclosure having an interior and an acoustic window; a second electrical connector configured to be removably connectable to the first electrical connector; a high intensity focused ultrasound transducer mounted in the interior and in electrical communication with the second electrical connector, the high intensity focused transducer configured and arranged, when the cartridge is connected to the body, to deliver high intensity focused ultrasonic energy through the acoustic window when the high intensity focused transducer is energized via the first electrical connector and the second electrical connector: a coupling liquid sealed within the sealed enclosure; and a heat exchanger (614, 750) having a third fluid connector removably connectable to the first fluid connector and a fourth fluid connector removably connectable to the second fluid connector and the heat exchanger (614, 750) configured to receive therethrough, when the cartridge is mounted to the body, a flow of cooling fluid via the first, second, third and fourth fluid connectors, the flow of cooling fluid for cooling the coupling liquid; the cartridge being configured so that the cartridge is mountable to the body, with the first electrical connector connecting to the second electrical connector, the first fluid connector connecting to the third fluid connector, and the second fluid connector connecting to the fourth fluid connector without removing the high intensity focused transducer from the sealed enclosure characterized in that the heat exchanger (614, 750) is mounted in the interior of the sealed enclosure. a sealed enclosure, the sealed enclosure configured to be removably mountable to the body, and the sealed enclosure having an interior and an acoustic window; a second electrical connector configured to be removably connectable to the first electrical connector; a high intensity focused ultrasound transducer mounted in the interior and in electrical communication with the second electrical connector, the high intensity focused transducer configured and arranged, when the cartridge is connected to the body, to deliver high intensity focused ultrasonic energy through the acoustic window when the high intensity focused transducer is energized via the first electrical connector and the second electrical connector: a coupling liquid sealed within the sealed enclosure; and a heat exchanger (614, 750) having a third fluid connector removably connectable to the first fluid connector and a fourth fluid connector removably connectable to the second fluid connector and the heat exchanger (614, 750) configured to receive therethrough, when the cartridge is mounted to the body, a flow of cooling fluid via the first, second, third and fourth fluid connectors, the flow of cooling fluid for cooling the coupling liquid; the cartridge being configured so that the cartridge is mountable to the body, with the first electrical connector connecting to the second electrical connector, the first fluid connector connecting to the third fluid connector, and the second fluid connector connecting to the fourth fluid connector without removing the high intensity focused transducer from the sealed enclosure