Keywords: System Imperfections, Low-Field MRI, Eddy currents measurement
Motivation: Significant field inhomogeneity, more pronounced residual magnetism of supporting structure, and field drift over time of portable systems preclude accurate eddy currents measurement.
Goal(s): To propose a fast eddy currents measurement and correction method based on field probe, tailored to the characteristics of portable low-field systems.
Approach: A frequency correction term was introduced in the probe localization sequence. The testing gradients and fitting algorithms for the eddy currents measurement were optimized. The correction quality was evaluated in vivo with diffusion-weighted EPI.
Results: The calibration took approximately 5min, reducing eddy currents to below 0.03% and effectively minimizing distortions in DW-EPI.
Impact: Eddy currents in a samarium cobalt two-plate permanent magnet portable design can be reliably characterized in 5 minutes, which can be used to minimize impacts of field inhomogeneity, instability, and remanence, as well as improving clinical image quality (e.g., DWI).
How to access this content:
For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.
After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.
After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.
Keywords