Transurethral ultrasound catheter-based transducer with flexible polyimide joints

Transurethral ultrasound (TUUS) may improve prostate imaging by providing real-time volumetric imagery from directly within the prostate. A transurethral ultrasound transducer prototype was developed that features a cylindrical 2D array of piezoelectric elements that can be integrated with a catheter body. Fabrication of the transducer was made possible with a microfabrication process that allows the array to be rolled and wrapped circumferentially. The transducer array prototype features bulk lead zirconatetitanate (PZT) elements mounted on an array of silicon islands connected by flexible patterned polyimide joints. A preliminary image reconstruction simulation, developed specifically for the cylindrical architecture was performed to demonstrate the potential resolving capability in the prostate environment. Together the results of the transducer fabrication and image reconstruction indicate that the cylindrical transducer array approach is feasible for TUUS. Future clinical application of the technology may lead to considerable improvement in prostate imaging, image guidance, and monitoring as a new high resolution, real-time imaging tool.