Keywords: In Silico, Simulation/Validation
Motivation: Balancing B1+ homogeneity and power efficiency with SAR reduction remains a challenge at 7T. RF shimming of multi-channel transmit coils can address that challenge.
Goal(s): To develop and assess an RF shimming strategy for 7T RF coils with high transmit channel density to obtain low levels of SAR and extended B1+ coverage.
Approach: A multi-ROI, histogram loss based shimming strategy is used to optimize B1+. A SAR-shimming strategy follows to reduce SAR while maintaining similar B1+.
Results: A histogram based B1+ shimming algorithm enables homogeneous, whole-brain B1+. SAR-shimming is able to reduce SAR while maintaining similar B1+ to the initial conditions.
Impact: Multi-ROI RF shimming using histogram loss is successful at optimizing B1+ throughout the brain. By performing B1+-restrictive RF shimming with SAR-heavy cost functions, the electromagnetic fields of a multichannel transmit array are manipulated to maintain B1+ conditions while reducing SAR.
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