Medical ultrasound systems. A base unit is included having system electronics, a user interface and ultrasound control electronics. An ultrasound therapy head is in electronic communication with the base unit. The therapy head includes a replaceable, sealed transducer cartridge with a coupling fluid therein. A cooling system is provided for cooling the coupling fluid. A plurality of guide indicators are positioned around the therapy head to align with crossed lines on a patient so as to properly align the therapy head prior to use. The therapy head can provide variable treatments to an area while the therapy head is in contact with a patient.