Enhanced cardiac motion capture during respiration via RF receiver cardiac focusing with respiratory motion compensation

Motivation: Cardiac MRI is hindered by respiratory motion. Goal(s): To improve the representation of cardiac motion over respiratory motion and to reduce artifacts for cardiac- and respiratory-resolved imaging. Approach: We added retrospective cardiac phased array RF focusing using region-optimized virtual coils (ROVir) alongside rigid motion compensation (MoCo) for low-rank tensor (LRT) reconstruction of ROCK-MUSIC data in pediatric congenital heart disease (CHD) patients. Evaluation metrics targeted cardiac motion prioritization, cardiac energy preservation, respiratory motion suppression, and flickering artifact reduction. Results: The proposed techniques compensated respiratory motion over the heart, prioritized cardiac motion, diminished respiratory motion, and removed artifacts, while also accelerating reconstruction time. Impact: The combination of MoCo and ROVir prioritizes modeling of cardiac motion, suppresses respiratory motion, and reduces artifacts. The improved respiratory handling from these techniques may provide an avenue for free-breathing scanning in pediatric patients with CHD.