Precision-Driven MRI Data Recovery: Integrating SAGE Trajectory Optimization with PROPELLER Acquisition

Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) magnetic resonance imaging (MRI) offers distinct advantages in compensating for bulk physiological motions, including head movement and free breathing artifacts. This non-Cartesian acquisition technique exhibits dual capabilities for magnetic field inhomogeneity correction and motion-insensitive imaging, with demonstrated clinical efficacy in neuroimaging involving involuntary head motion and free-breathing cardiac imaging. However, its reconstruction fidelity remains susceptible to gradient timing delays inherent in MRI system hardware. To address this limitation, we introduced a Simultaneous Auto-calibration and Gradient Delay Estimation (SAGE) framework for $\mathrm{k}$-space trajectory rectification. Through systematic delay simulations and trajectory compensation applied to both phantom studies and in vivo human datasets, our experimental results qualitatively demonstrated significant artifact reduction and successfully validated the feasibility of this compensation methodology.