Real-time 3D ultrasound with multiple transducer arrays

Modifications were made to a commercial real time 3D ultrasound system for near simultaneous 3D scanning with two 2D array transducers. As a first illustration, a transducer cable assembly was modified to incorporate two independent 3D intracardiac echo catheters, a 7 Fr (2.3 mm O.D.) side scanning catheter and a 14 Fr (4.7 mm O.D) forward viewing catheter with tool port, each using 85 channels operating at 5 MHz. For applications in treatment of atrial fibrillation, the goal is to implant the side-viewing catheter within the coronary sinus to view the whole left atrium including left pulmonary veins. Meanwhile the forward viewing catheter inserted within the left atrium is directed toward the os of a pulmonary vein for therapy using the integrated tool port. Using pre-loaded phasing data, the scanner switches between catheters automatically at the push of a button with a delay of about 1 second so that the clinician can view the therapy catheter with the coronary sinus catheter and vice versa. In the future, the system will switch between 3D probes on a frame-by-frame basis. We may also test the feasibility of image fusion using multiple 3D cardiac scans.