Whole-heart coronary magnetic resonance angiography - Contrast-enhanced high-resolution, time-resolved 3D imaging

Objectives: To test the feasibility and performance of a 4D magnetic resonance coronary angiography sequence compared with conventional inversion recovery (IR) prepared gradient echo imaging. Materials and Methods: A 4D sequence with 100 milliseconds temporal resolution was implemented on a 1.5 T system. Five minipigs were examined after administration of very small superparamagnetic iron oxide particles. Coronary angiographies with an isotropic resolution of 0.82 mm were performed in the pigs using 4D and IR sequences. Results: The 4D sequence allowed visualization of the coronary arteries, the effect of their movement and that of the entire heart without prolonging scan time. The contrast-to-noise ratio of the IR images was on average 38% higher than that of the corresponding 4D phase. Conclusions: 4D magnetic resonance imaging is superior in that no trigger delay time needs to be determined and an additional whole-heart cine study can be obtained.