Image-based navigation (iNAV) is a promising respiratory
motion correction approach for coronary MR angiography (CMRA). However, for dual-phase
CMRA the technique may fail due to the different cardiac motion states of the systolic
and diastolic acquisition. Here we propose the use of separate independent systolic
and diastolic iNAV acquisitions to address this issue. We compared iNAV to the
conventional diaphragmatic one-dimensional navigator (1D NAV) in 8 healthy
subjects. The proposed technique achieves similar or improved coronary vessel
sharpness compared to 1D NAV while reducing dual-phase CMRA acquisition time.
