An ultrasound catheter is described herein for insertion into a cavity such as a blood vessel to facilitate imaging within a vasculature. The catheter comprises an elongate flexible shaft, a capacitive microfabricated ultrasonic transducer, and a sonic reflector. The elongate flexible shaft has a proximate end and a distal end. A capacitive microfabricated ultrasonic transducer (cMUT) is mounted to the shaft near the distal end. The reflector is positioned such that a reflective surface redirects ultrasonic waves to and from the transducer. In other embodiments, the catheter comprises a plurality of cMUT elements and operates without the use of reflectors. In further embodiments, integrated circuitry is incorporated into the design.