In one embodiment of the present invention, a system for treating an occlusion within a patient's vasculature with ultrasonic energy comprises a catheter configured to be passed through the patient's vasculature such that a portion of the catheter is positioned at an intravascular treatment site. The system further comprises an ultrasound radiating member, an ultrasound signal generator configured to supply a drive signal to the ultrasound radiating member, an infusion pump configured to pump a therapeutic compound into the fluid delivery lumen so as to cause the therapeutic compound to be delivered to the treatment site and a controller configured to control the ultrasound signal generator and the infusion pump.