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Abstract #2387

High-Order B0 Shimming with Compensating RF Pulses Enables Efficient and Uniform Flip Angles

Vincent Oltman Boer1, Irene M.L. van Kalleveen2, Peter R. Luijten2, Robin A. de Graaf3, Dennis W.J. Klomp2

1Radiology, University Medical Center Utrecht, Utrecht, NL, Utrecht, Netherlands; 2Radiology, UMC Utrecht, Utrecht, NL, Utrecht, Netherlands; 3Department of Diagnostic Radiology, Yale University, New Haven, CT, United States

Here we show how the additional degrees of freedom of a higher order B0 shim system can be utilized to compensate the flip angle variations generated by RF coils. The principle of compensation relies on linking spatially similar B0 and B1 distributions with an RF pulse with an appropriate frequency response. Experimental results in the human brain at 7T show that a compensating RF pulse in combination with a third order B0 offset field can mitigate the flip angle variations associated with a surface coil.