Processing and Analysis of Cardiac Signals for MRI Triggering

Magnetic resonance imaging (MRI) has advanced to provide critical insights into tissue, functionality, and metabolic processes. However, higher magnetic fields (up to 7 T) introduce challenges in clinical practice, particularly in motion compensation during imaging. Timed-triggered imaging is essential for high-quality diagnostics, making the precision of cardiac signal acquisition methods crucial. This study evaluates three such methods in an MRI setting-ECG, photoplethysmography (PPG), and ballistocardiography (BCG)-using data from 32 volunteers. Peak analysis showed PPG achieved the highest accuracy in pulse wave detection (F1 score 99.21 %), followed by BCG with J-wave detection (F1 score 91.15 %), while ECG, limited by magnetic interference, achieved only a 70.97% F1 score in R-wave detection. These results indicate that PPG is the most reliable method for MRI triggering, with BCG as a viable alternative. Conversely, ECG's susceptibility to interference limits its reliability in high-field MRI environments. These findings could enhance cardiovascular imaging practices and expand clinical applications of biological signal acquisition.