An open-source shim generation workflow for permanent magnet MRI systems

Motivation: One of the most challenging steps in constructing a low-field MRI scanner is shimming. At the present time, there are no general-purpose low-field shim generation tools. Goal(s): To develop a workflow to generate permanent magnet shims for low-field scanners. Approach: A modular, python-based workflow has been developed that can produce a set of CAD files for a shim design from a B0 map of the magnet to be shimmed and a CAD template file. Results: Two sites tested the shim generation part of the workflow, and one site was able to construct and measure the generated shim design. Impact: An open-source workflow was developed to streamline the design of permanent magnet shims for low-field permanent magnet scanners. This will make shimming, one of the most challenging parts of permanent magnet construction, easier and more accessible.