Stretched Radial Trajectory Design for Improved K-space Coverage and Effective Image Resolution

Motivation: Conventional radial sampling cannot cover full k-space, therefore reducing effective resolution. This study aims to enhance k-space coverage without increasing scan times. Goal(s): Develop and validate a "stretched radial" sampling trajectory to improve k-space coverage and image resolution while keeping gradient performance and time constraints. Approach: Design a stretched trajectory scheme, implementing on 2D, 3D, and spiral projection sampling, and compared with conventional methods through phantom and in-vivo MRI experiments. Results: The proposed method successfully enhanced resolution and image sharpness without increasing acquisition time, effectively improving details for both phantom and in-vivo data. Impact: The stretched radial trajectory enables sharper MRI imaging without longer scan times, benefiting clinicians with improved diagnostic detail, and requires minimal efforts to implement. This innovation enhances imaging in low-performance MRI systems, potentially extending advanced diagnostics to underserved regions.