ECG-GatedInterventionalCardiac.PDFVIP

ECG-Gated Interventional Cardiac Reconstruction for Non-periodic Motion Christopher Rohkohl1,2,G¨unter Lauritsch2, Lisa Biller2, and Joachim Hornegger1 1 Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander University Erlangen-Nuremberg, 91058 Erlangen, Germany 2 Siemens AG, Healthcare Sector, 91301 Forchheim, Germany Abstract. The 3-D reconstruction of cardiac vasculature using C-arm CT is an active and challenging ?eld of research. In interventional envi- ronments patients often do have arrhythmic heart signals or cannot hold breath during the complete data acquisition. This important group of pa- tients cannot be reconstructed with current approaches that do strongly depend on a high degree of cardiac motion periodicity for working prop- erly. In a last year’s MICCAI contribution a ?rst algorithm was presented that is able to estimate non-periodic 4-D motion patterns. However, to some degree that algorithm still depends on periodicity, as it requires a prior image which is obtained using a simple ECG-gated reconstruction. In this work we aim to provide a solution to this problem by developing a motion compensated ECG-gating algorithm. It is built upon a 4-D time- continuous a?ne motion model which is capable of compactly describing highly non-periodic motion patterns. A stochastic optimization scheme is derived which minimizes the error between the measured projection data and the forward projection of the motion compensated reconstruc- tion. For evaluation, the algorithm is applied to 5 datasets of the left coronary arteries of patients that have ignored the breath hold com- mand and/or had arrhythmic heart signals during the data acquisition. By applying the developed algorithm t