Prospective Respiratory Navigator Gated RF Excitation in Whole-heart Coronary MRA at 3T

Figure 1. Illustration of profile filling order in k-space for whole-heart 3D coronary MRA. (a) For the concentric elliptical filling order, dark blue profiles in the center are acquired first during one heart-beat while dark red profiles are acquired at the end of the same heartbeat. An angular increment is performed for subsequent heartbeats. (b) Using the conventional profile filling order in k-space in conjunction with the prospective navigator gated RF excitation, high (white) and low (grey) signal intensity profiles are randomly distributed in k-space. With the proposed reordering method (c), profiles of high steadystate signal are grouped together to maximize SNR and minimize unwanted image artifacts.