TY - JOUR A1 - Brost, Joachim A1 - Wimmer, Andreas A1 - Liao, Rui A1 - Bourier, Felix A1 - Koch, Martin A1 - Strobel, Norbert A1 - Kurzidim, Klaus A1 - Hornegger, Joachim T1 - Constrained registration for motion compensation in atrial fibrillation ablation procedures JF - IEEE Trans Med Imaging N2 - Fluoroscopic overlay images rendered from preoperative volumetric data can provide additional anatomical details to guide physicians during catheter ablation procedures for treatment of atrial fibrillation (AFib). As these overlay images are often compromised by cardiac and respiratory motion, motion compensation methods are needed to keep the overlay images in sync with the fluoroscopic images. So far, these approaches have either required simultaneous biplane imaging for 3-D motion compensation, or in case of monoplane X-ray imaging, provided only a limited 2-D functionality. To overcome the downsides of the previously suggested methods, we propose an approach that facilitates a full 3-D motion compensation even if only monoplane X-ray images are available. To this end, we use a training phase that employs a biplane sequence to establish a patient specific motion model. Afterwards, a constrained model-based 2-D/3-D registration method is used to track a circumferential mapping catheter. This device is commonly used for AFib catheter ablation procedures. Based on the experiments on real patient data, we found that our constrained monoplane 2-D/3-D registration outperformed the unconstrained counterpart and yielded an average 2-D tracking error of 0.6 mm and an average 3-D tracking error of 1.6 mm. The unconstrained 2-D/3-D registration technique yielded a similar 2-D performance, but the 3-D tracking error increased to 3.2 mm mostly due to wrongly estimated 3-D motion components in X-ray view direction. Compared to the conventional 2-D monoplane method, the proposed method provides a more seamless workflow by removing the need for catheter model re-initialization otherwise required when the C-arm view orientation changes. In addition, the proposed method can be straightforwardly combined with the previously introduced biplane motion compensation technique to obtain a good trade-off between accuracy and radiation dose reduction. Y1 - 2012 U6 - https://doi.org/10.1109/tmi.2011.2181184 VL - 31 IS - 4 SP - 870 EP - 881 ER - TY - CHAP A1 - Küchler, Andreas A1 - Schober, F. A1 - Liebschner, M. A1 - Berger, Frank A1 - Exner, W. A1 - Krause, Ch. A1 - Fritsche, R. A1 - Wimmer, R. T1 - Dielectric Behaviour of HVDC Insulating Materials, Polarization and Conduction Processes in Mineral Oil and in Pressboard Impregnated with Different Fluids T2 - 19th International Symposium on High Voltage Engineering Y1 - 2015 CY - Pilsen, Czech Repbulic ER -