Numerical Evaluation of the Specific Absorption Rate Change of Transmit Arrays at 9.4T due to Presence of B0 Field Probes

Motivation: Imperfections of B0-field can reduce the MR image quality. To track the B0 change during imaging, NMR field-probes inside the RF coil can be used. Insertion of the field-probes may lead to alteration of the B1+ and pSAR. Goal(s): To evaluate alterations of B1+ field and pSAR of the 16-channel Tx-array in the presence of NMR field-probes at 9.4T. Approach: To reach the goal, we simulated the Tx-part of the 16Tx32Rx array loaded by a phantom and human voxel model in the presence of 11 field-probes. Results: Insertion of field-probes led to a small drop of B1+ and a slight change of pSAR. Impact: We showed that inserting field-probes doesn’t significantly alter the B1+ field and pSAR of the 16Tx32Rx array coil at 9.4T. Therefore, field-probes can be safely used in-vivo to evaluate B0.