The spatial and temporal fidelity in real-time MRI in patients with sinus rhythm and arrhythmias

Background Irregularly irregular arrhythmia is difficult to image with conventional cine CMR because arrhythmia rejection and registration-based reconstruction result in cardiac motion artifacts or unachievable breath-hold durations. Undersampled radial trajectories, combined with a suitable non-Cartesian reconstruction algorithm, have the potential to overcome these problems by sampling a small number of radial projections without loss of temporal fidelity associated with temporal regularization. Despite the large number of available real-time reconstruction algorithms and sampling trajectories, there are very few reports regarding optimal values for basic reconstruction parameters such as image exposure time (radial projections per image frame) and temporal resolution (view sharing). Our goal was to address the problem of spatial and temporal fidelity in real-time MRI using automatic active contour segmentation in subjects with sinus rhythm and also patients with irregularly irregular arrhythmias.