The present invention relates to an ultrasound system comprising an ultrasound catheter for disrupting occlusions in blood vessels, the ultrasound catheter comprising: an elongate flexible catheter body having a proximal end, a distal end, at least one lumen extending longitudinally through the body； an ultrasound transmission member extending longitudinally through the lumen of the catheter body, the ultrasound transmission member having a proximal end connectable to a separate ultrasound generator and a distal end disposed adjacent the distal end of the catheter body； and a distal head coupled with the distal end of the ultrasound transmission member, the distal head positioned adjacent the distal end of the catheter body； wherein the ultrasound transmission member transmits at least two different types of ultrasound energy from the separate ultrasound generator, the ultrasound system further comprising the ultrasound generator.
