Stop-Motion RF for Improving Spatial Resolution in Non-Linear Gradient-Free Low-Field MRI

We developed a stop-motion imaging technique in which a 3x3 radiofrequency coil that transmits Bloch-Siegert encodings is placed in a different position within the field-of-view for each MR signal acquisition. This study is performed using a non-linear gradient-free low-field MRI system. High spatial resolution is achieved through stop-motion imaging. We show that stop-motion imaging done with a total of 200 encodings (20 imaging positions and 10 encodings per position) outperformed stationary imaging performed with 200 encodings (1 imaging position and 200 encodings per position).