Research on spatial resolution in cardiac source imaging for multiple measurement modes using a realistic multi-tissue human model

Magnetocardiography (MCG) and electrocardiography (ECG) are noninvasive techniques that reflect cardiac electrical activity. Combined MCG and ECG (MECG) integrates both measurements, and due to technological advancements, vector MCG (vMCG) is now possible. Although all four modes—MCG, ECG, MECG, and vMCG—are used in cardiac source imaging, their spatial resolutions have not been systematically studied. This study evaluates these modes using a resolution matrix based on a realistic multi-tissue human model, analyzing their dependence on source direction, location, and signal-to-noise ratio. Results show that MECG and vMCG significantly reduce dependence on these factors, with vMCG offering superior spatial resolution. However, its advantage lessens as SNR decreases. Our findings suggest that MECG and vMCG enhance spatial resolution in cardiac source imaging, making them promising options for future research.