Time-resolved cardiac cone beam CT using an interventional C-arm system

It is both desirable and challenging to make interventional C-arm systems fit for cardiac cone beam CT. A number of methods towards this goal have been proposed, some of which even attempt to generate 4D images of the beating heart. A promising candidate of this type, proposed in [10, 12], is based on the (provable) assumption that the 3D image of the patient’s thorax at an arbitrary heart phase is a spatially deformed version of a 3D reference image at some reference phase. Under this assumption, the proposal goes on, it should be possible to jointly reconstruct reference image and deformation field using a nonlinear extension of the Algebraic Reconstruction Technique. Meanwhile, the proposed reconstruction algorithm has been implemented and tested with simulated and clinical data. The results are favorable: Reconstructed 4D images show the heart beating. In the simulated case, where the true 4D image is known, the reconstructed motion compares well with the true motion.