Influence of the k ‐space trajectory on the dynamic T 1 ‐weighted signal in quantitative first‐pass cardiac perfusion MRI at 3T

The dynamic T 1 ‐weighted signal in first‐pass myocardial perfusion MRI can vary as a function of k ‐space trajectory. The purpose of this study, therefore, was to compare the relative T 1 ‐weighted signal produced by the linear, centric, and reverse centric k ‐space trajectories at 3T. The centric k ‐space trajectory yielded higher arterial input function (AIF) than the linear and reverse centric k ‐space trajectories (6.21 ± 0.84 vs. 4.75 ± 0.75 vs. 4.39 ± 0.85 mM, respectively; N = 9; P < 0.01), and the reverse centric k ‐space trajectory yielded higher myocardial signal contrast (as a fraction of equilibrium magnetization) than the linear and centric k ‐space trajectories (0.17 ± 0.02 vs. 0.12 ± 0.02 vs. 0.05 ± 0.01, respectively; N = 9; P < 0.001). Compared to the linear k ‐space trajectory, the centric k ‐space trajectory is relatively optimal for the quantification of AIF, whereas the reverse centric k ‐space trajectory is relatively optimal for high contrast of myocardial wall enhancement. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.