Evaluation of 3D Radial Phyllotaxis Trajectories for Artifact-Free Imaging and Parametric Mapping

Motivation: Using the original 3D radial spiral phyllotaxis trajectory leads to image artifacts and parametric mapping inaccuracies. Goal(s): To develop two alternative 3D radial phyllotaxis trajectories enabling artifact-free images and accurate parametric mapping. Approach: Evaluate two trajectories that (1) sample opposite radial spokes and (2) avoid jumps in k-space. Compare image quality and parametric maps obtained using the new trajectories in a phase-cycled bSSFP sequence with the original phyllotaxis and a Cartesian trajectory. Results: The two alternative 3D radial trajectories mitigate artifacts and significantly reduce errors in T1,T2 estimation in phantoms and in the brain of three healthy volunteers, compared with the original implementation. Impact: The proposed 3D radial phyllotaxis trajectory designs reduce artifacts and improve T1,T2 mapping accuracy, enhancing image quality for researchers using 3D radial imaging across MRI sequences, including bSSFP. These designs enable accurate radial imaging in both research and clinical applications.