Catheter arrays: can intravascular ultrasound make a difference in managing coronary artery disease

There are two primary reasons why intravascular ultrasound has not yet reached its potential for interventional cardiology. First, image quality has been poor given the possible operating frequencies and numerical apertures. And second, there is no application where routine imaging critically guides an intervention. Over the last 5 years, the Biomedical Ultrasonics Lab at the University of Michigan and Endosonics Corporation have worked together to directly address these issues. Recent progress strongly suggests that both limitations can be overcome. First, image quality has been greatly improved with a real-time, synthetic phased array system using a 64 element, high efficiency, ceramic piezoelectric transducer operating at 20 MHz. The array is mounted on the surface of a 1.2 mm diameter catheter appropriate for intracoronary imaging. Second, using this high performance system, three new applications of intraluminal ultrasound have been investigated: real-time color flow imaging, in situ elasticity measurements, and stent deployment monitoring. In this paper, the results of this work are reviewed.