New 3-D imaging catheter aims to reduce risk of complications during cardiac interventions

An emerging 3-D imaging catheter aims to provide cardiologists with a live view from inside the heart during cardiac catheterizations. Developed by RTI International, the catheter contains an ultrasound microarray made using semiconductor circuit fabrication that can provide unprecedented volumetric field-of-view, in real time.

Providing this live 3-D view could help improve accuracy and reduce the risk of complications during cardiac interventions, according to researchers. This improved visualization could also shorten interventional procedures that currently can take several hours to complete due to their complex nature and limited ability to see inside the heart.

"Unlike other silicon-based ultrasound devices, this microarray technology combines the performance benefits of conventional piezoelectric devices with the miniaturization and manufacturing efficiency of semiconductor microfabrication," said lead author David Dausch, Ph.D., Technical Director at RTI.

This technique enabled RTI to produce ultrasound arrays with up to 512 piezoelectric elements, eight times more than conventional 2-D ultrasound catheters. The first-ever real-time 3-D ultrasound images from this type of ultrasound device were reported in an article published in the IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Full 3-D volumes with field-of-view of 60 by 60 degrees were obtained in a live porcine model with frame rates of up to 30 volumes per second.

RTI has teamed with a southern-California based entrepreneur, Dr. Paul Zalesky, to form Envisage Medical, Inc., a startup company aimed at developing the volumetric imaging system necessary to advance this technology into clinical reality.

"Our goal is to give the interventionalist a simple, intuitive imaging tool that will streamline the workflow and improve outcomes," Zalesky said. According to Zalesky, the silicon-based manufacturing platform will reduce cost, ultimately providing 3-D imaging at a cost lower than today's 2-D imaging.

RTI is also collaborating with Dr. Kalyanam Shivkumar, Director and Chief of Interventional Cardiovascular Programs at UCLA Medical Center, with the goal of implementing this technology in the catheter lab.

"This is likely to revolutionize interventional therapies in electrophysiology and structural heart disease," Shivkumar said.

The project team's next steps are to integrate the 3-D catheters onto a clinical ultrasound system and demonstrate efficacy in a series of animal studies. The team hopes that in the near future this real-time volumetric imaging technology can be used by interventional cardiologists to guide the repair and replacement of heart valves, correction of dangerous arrhythmias, and other least invasive cardiac procedures.