Self-Gating Reconstruction of Multiple Respiratory Phases using Undersampled Golden-Radial Phase Encoding Trajectory

INTRODUCTION: Navigator gating is a proven approach to reduce respiratory motion artifacts in free-breathing 3D MRI. Moreover, self-gating techniques to avoid steady state interruption [1, 2], and automatic navigator window selection of the most common respiratory phase [3], have been proposed. However, the most common respiratory position does not necessarily give the best image quality, as has been shown in [4]. Here, we propose a new self-gating radiallike acquisition scheme which allows the retrospective undersampled reconstruction of different high resolution respiratory phases, giving the operator the choice of the best phase as in [4]. This approach takes advantage of the recently introduced Golden-Radial Phase Encoding (G-RPE, [5, 6]) trajectory and uses the, inherently acquired, central k-space profiles (c-ksp) to derive the respiratory signal. Moreover, an image quality surrogate has been derived to estimate prospectively the set of respiratory positions which can be reconstructed with appropriate image quality.