Fast Spin Echo Approach for Accelerated B1-gradient Based MRI

Recent efforts to expand access to MRI have focused on low-cost, portable MRI systems that eliminate pulsed B0 gradients in favor of radio-frequency imaging techniques. In this work we present a new multi-echo version of FREE (Frequency-modulated Rabi Encoded Echoes) that utilizes nonlinear B1+ gradients to perform spatial encoding. This new technique leverages the acceleration of conventional FSE approaches and nonlinear gradients to eliminate the need for conventional B0 gradients while also achieving very high spatial resolution.