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. (C) 2016 International Society for Magnetic Resonance in Medicine