Rapid Image Registration of Three-Dimensional Transesophageal Echocardiography and X-ray Fluoroscopy for the Guidance of Cardiac Interventions

The recent availability of three-dimensional (3D) transesophageal echocardiography (TEE) provides cardiologists with real-time 3D imaging of cardiac anatomy. X-ray fluoroscopy is the conventional modalilty that is used for guiding many cardiac interventions. Increasingly this is now supported using intra-procedure 3D TEE imaging. We hypothesize that the real-time co-registration and visualization of 3D TEE and X-ray fluoroscopy data will provide a powerful guidance tool for cardiologists. In this paper, we propose a novel, robust and efficient method for performing this registration. Our method consists of an image-based TEE probe localization algorithm and a calibration procedure. While the calibration needs to be done only once, the registration takes approximately 9.5 seconds to complete. The accuracy of our method was assessed by using both a crosswire phantom and a more realistic heart phantom. The target registration error for the heart phantom was less than 2mm. In addition, the accuracy and the clinical feasiblity of our method was evaluated in two cardiac electrophysiology procedures. The registration results showed inplane errors of 1.5 and 3mm.