Self-Navigator for Free-Breathing 3D SSFP Cardiac Imaging: Center of Mass Along the Slice Direction Versus the Image Signal Sum Using the Center of K-Space.

Pascal Spincemaille¹, Jing Liu¹, Thanh Dang Nguyen¹, Martin Prince¹, Yi Wang¹

The k-space center signal has been used for self-navigating of respiratory motion that is very useful for SSFP imaging. However, this signal is slice location and geometry dependent and is affected by blood flow and heart motion, which may lead to ineffective motion sensitization. In this study, the kz axis is repeatedly sampled and Fourier transformed to generate a projection of the image volume onto the slice axis. The center-of-mass of this projection is proposed as a respiratory gating signal and is shown to provide superior respiratory motion artifact suppression when compared to the use of the center-of-k-space signal only.