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Influence of the k‐space trajectory on the dynamic T1‐weighted signal in quantitative first‐pass cardiac perfusion MRI at 3T

The dynamic T1‐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 T1‐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.