Intra-MRI extraction of diagnostic electrocardiograms using dynamic feedback from carotidal magnetohydrodynamic voltages

Background During Cardiac Magnetic Resonance Imaging (CMR), blood plasma electrolytes ejected into the aorta during early systole interact with the static magnetic field of the MR scanner (B0) to produce a Magnetohydrodynamic (MHD) Effect [1]. Electrocardiograms (ECGs) recorded in the presence of B0 are overlaid with induced MHD voltages (VMHD), leading to non-robustly synchronized imaging [2], and preventing reliable physiological monitoring inside the MRI [3]. Previous methods have sought to separate between VMHD and the true ECG (ECGreal) through adaptive filtering [3], independent component analysis [4], and advanced computational models [5]. However, these methods are based on a static model, which has limited accuracy during varying-rate heart-beats. We aim to develop accurate ECGreal extraction, as well as real-time Stroke Volume (SV) estimation (proportional to the integral of MHD over systole) [6], with the advantage of physiological feedback through the real-time monitoring of common carotidal MHD, through which the previously static MHD template can be dynamically updated, providing an increased level of accuracy during variations in heart rate, and a continuous estimation of VMHD and ECGreal, for the patient’s entire duration inside the MRI.