An ultrasonic catheter includes a body and an ultrasound transmission member disposed in the body. A head is coupled to the ultrasound transmission member, wherein a gap separates the head from a body distal end. A guidewire tube extends through the body and the head. A proximal end connector assembly includes a hub and an absorber member. The hub has a bore coupled to and in fluid communication with the body. The absorber member is disposed within the bore around the ultrasound transmission member. A sonic connector is disposed between the ultrasound transmission member and a separate generator.