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Abstract #3462

Parallel Transmit SAR Estimation Using FDTD Modeling in the Human Head at 7T

Mohammad Mehdi Khalighi1, Priscilla Chan2, Brian K. Rutt3

1Global Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 2Electrical Engineering Department, Stanford University, Stanford, CA, United States; 3Radiology Deaprtment, Stanford University, Stanford, CA, United States

Present methods of measuring SAR are insufficient to verify safety in MR scans at high field especially with the use of parallel transmit. An FDTD-modeling software package with realistic body models was used to model SAR using either quadrature (qTx) or 2-channel parallel (pTx) transmit with a birdcage head coil. These numerical simulations were validated by comparison to experimentally-measured in-vivo B1+ fields. SAR and B1+ uniformity were compared between qTx and different pTx pulses; results show that pTx pulses with greater number of spokes create better uniformity and lower average SAR with similar SAR hot spot distribution compared to qTx.