New pulse sequence for improving cardiac black-blood and PSIR MRI quality in cases of arrhythmia

Most conventional cardiac MRI scans, which rely on electrocardiogram (ECG)-triggered segmented acquisition for k-space data, are highly sensitive to arrhythmia-a vulnerability that can induce severe motion artifacts, thereby degrading image quality and diagnostic accuracy. This study developed a novel pulse sequence: an MRI-independent thread continuously records and analyzes the subject's heart rhythm throughout the entire scan, calculates key temporal parameters in real time, feeds them back to update the sequence dynamically based on actual rhythm, thereby reducing k-space data misalignment and eliminating motion artifacts. Experimental results showed that the new pulse sequence effectively improved cardiac black-blood T2-weighted and phase-sensitive inversion recovery (PSIR) image quality in cases of arrhythmia, and with broad application prospects for cardiac MRI in arrhythmic subjects. This "prevention-first" approach (rather than "repair-after") makes it highly clinically translatable, as it can be deployed on standard equipment without additional costs.