Toward image-based catheter tip tracking for treatment of atrial fibrillation

The use of 3-D patient-specific anatomical models in combination with an electromagnetic (EM) catheter tracking device has become the standard for guidance of pulmonary vein (PV) ablation. The anatomical model, derived from CT/MR-images, has to be registered to the EM tracking system by means of a time consuming procedure and the use of these EM systems comes with a high associated cost. We present a method for determining the ablation catheter tip position with respect to a 3-D model, without the need for an EM tracking device. Using only biplane fluoroscopy, the ablation catheter tip can be tracked and visualized in conjunction with a patient-specific 3-D anatomical model. Tip tracking is realized by a discrete image pattern tracking technique which is regularized using a Kalman filter. The method was integrated in a software suite for image guided treatment of catheter ablation procedures to test its usability in a real clinical setting. An accuracy evaluation was performed on several image sequences, recorded during actual procedures. The tracking method is able to track the 2-D location and reconstruct the 3-D pose of the tip for several sequences of images with an accuracy of 1.7 mm. During several procedures the tracking approach was tested and performed well over periods of several minutes after which reinitialization was needed. The proposed approach can offer an alternative for EM tracking systems for integrated 3-D visualization of the ablation catheter tip and a 3D model. Since neither specific hardware nor dedicated catheters are needed, the associated usage cost of this approach is much less compared to EM tracking systems.