Influence of the k-space trajectory on the dynamic T1-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.