Registration of Atrium Models to C-arm X-ray Images Based on Devices Inside the Coronary Sinus and the Esophagus

For augmented fluoroscopy in the context of minimally invasive EP procedures, a patient-specific model of the atrium segmented from a 3-D volume can be overlaid on fluoroscopic images. This requires a registration between the 3-D model coordinate system and the coordinate system of the C-arm X-ray device. We propose an indirect registration that makes use of surrounding anatomical structures that can be segmented both in the 3-D volume obtained by CT or MRI and also in fluoroscopic images. More precisely, the coronary sinus and the esophagus segmented from the 3-D volume is registered to reconstructed 3-D devices which are located in the respective structures during the intervention. An evaluation on 6 images of 6 different patients yielded a mean registration error of 3.2mm. Results became significantly worse if only one of the anatomical structures was used.