Reducing ringing artifacts in dynamic pulmonary MRI with a golden-step based interleaving approach for 3D ultra-short TE acquisition

Motivation: In 3D radial ultra-short TE based dynamic pulmonary MRI, 3D radial k-space is usually segmented into multiple interleaves for interleaved acquisition. Motion-resolved k-space data are obtained subsequently by retrospectively binning using respiratory signals. Diaphragm drifting has been commonly observed during the scan, resulting in non-uniform spherical distribution of sampling density in motion-resolved k-space and ringing artifacts in reconstructed images. Goal(s): To reduce ringing artifacts in motion-resolved images. Approach: A golden-step based interleaving approach is proposed to mitigate adversary effect of diaphragm drifting. Results: Ringing artifacts in dynamic images acquired with conventional interleaving approach are significantly reduced in that acquired with proposed interleaving approach. Impact: Using golden-step based interleaving approach, uniform motion-resolved k-spaces can be obtained even under severe diaphragm drifting. This proposed approach has potential to reduce ringing artifacts in other non-Cartesian acquisitions and applications, such as bSSFP-based free-breathing cardiac MRI and real-time MRI.