"Random" non-linear encoded MRI on standard clinical MRI systems

Motivation: Encoding strategies using inhomogeneous magnetic fields offer new flexibility and/or acceleration of image acquisition. However, usually, additional hardware is required limiting its audience to a narrow range of sites. Goal(s): The goal of this work is the demonstration of image encoding on a clinical MRI system using inhomogeneous magnetic fields. Approach: The encoding capabilities of "random" encoding schemes were simulated and validated by using the already built-in higher-order shim coil to generate the inhomogeneous magnetic fields. Results: Despite long switching times of the shim coils, the higher-order shim terms were successfully used to encode an image in an ZTE-like fashion. Impact: This work demonstrates that the higher-order shim coils of a clinical MRI system can be utilized for first demonstrations of non-linear encoding schemes without the need of additional, mostly expensive and/or labour-intensive hardware.