Fig. 1.

Motion of a mid-RCA segment throughout the entire cardiac cycle reconstructed from a 4D coronary MRA acquisition: the coronary artery stayed relatively still during phases 1, 2, and 16, the systolic quiescent period, and phases 5–8, the diastolic quiescent period. All other phases exhibit significant intra-phase motion as evidenced by the blurry RCA segment. The conventional gating strategy places the acceptance window within one of the quiescent periods, e.g. phases 5–8 for this subject, while discarding the data from the other phases.