Abstract: A catheter is disclosed. The catheter includes an elongated body with an exterior surface and an ultrasound transducer with a longitudinal length. A support member supports the ultrasound transducer at the exterior surface of the elongated body and defines a chamber adjacent to the exterior surface of the elongated body. The chamber reduces transmission of ultrasound energy from the ultrasound transducer into the elongated body along the longitudinal length of the ultrasound transducer.

Abstract: A kit and method for causing tissue death within a tissue site is disclosed. The kit includes a media with a light activated drug activatable upon exposure to a particular level of ultrasound energy. The kit also includes a catheter with a lumen coupled with a media delivery port through which the light activated drug can be locally delivered to the tissue site. The ultrasound transducer is configured to transmit the level of ultrasound energy which activates the light activated drug with sufficient power that the ultrasound energy can penetrate the tissue site.