Figure 1

a) Center k-space point from radial acquisition, which was used in conventional cardiac self-gating method, shows cardiac motion signal with severe drifting and distortion; b) self-gating signal and triggers (marked by '*') detected by the proposed method on the same subject; c) self-gating and d) ECG signal with triggers on a different subject using a 3T scanner where the ECG fails to provide accurate triggers while the proposed method offers stable triggers.