A catheter includes a piezoelectric transducer mounted to the distal end of a catheter. In one embodiment, the piezoelectric transducer has the shape of a cylinder and in another embodiment, a convex shape with a mounting flange. In the cylindrical shape, a plurality of surface mounted temperature sensors are disposed within the piezoelectric transducer. The sensors are electrically insulated and a sealing technique prevents the leakage of body fluids from penetrating the interior of the catheter through the sensor bores. The cylindrical transducer is supported on mounting members so that it is accurately mounted and sealed while at the same time, the material used does not significantly dampen the transducer. The convex shape includes a temperature sensor at its tip.