Self‐gated cardiac cine imaging using phase information

Purpose To obtain multiphase cardiac cine images with high resolution, a novel self‐gating method for both cardiac and respiratory motions is proposed. Methods The proposed method uses the phase of projection data obtained from a separate axial slice to measure cardiac and respiratory motion, after the acquisition of every k‐space line in the image plane. Cardiac motion is estimated from the phase of the projection data passing through the aorta, which is amplified by superior–inferior directional bipolar gradients, whereas respiratory motion is estimated from the phase of the left–right directional projection data of the abdomen. To verify the proposed self‐gating method, a simulation and in vivo steady state free precession cardiac imaging were performed. Results The proposed method provides high resolution multiphase cardiac cine images. Using the proposed self‐gating method, the phase variation of the projection data offers information about cardiac and respiratory motions that is equivalent to external gating devices. Conclusion The proposed method can capture time‐resolved cardiac and respiratory motion from the phase information of the projection data. Because the projection data is obtained from a separate gating slice, the self‐gating signals are not affected by imaging planes. Magn Reson Med 77:1216–1222, 2017. © 2016 International Society for Magnetic Resonance in Medicine