Riccardo Lattanzi1,2, Yudong Zhu1, Daniel K. Sodickson1
1Center for Biomedical Imaging, NYU School of Medicine, New York, NY, USA; 2Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, USA
This work explores the electrodynamic behavior of transmit homogeneity and SAR for RF shimming. Ultimate SAR was calculated for uniform target excitation profiles both in a transverse and in a coronal plane through the center of a homogeneous cylinder. The trade-off between profile fidelity and SAR minimization was investigated in the ultimate case, as well as in the case of transmit arrays with increasing numbers of elements. Our simulations enforced homogeneity not only in the amplitude but also in the phase of the excitation profile, and the results suggest that this becomes a particularly stringent constraint at high field strengths.
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