Abstract #0393

Combined Loop + Dipole Arrays for 7 T Brain Imaging

Yigitcan Eryaman¹,², Bastien Gurin³, Robert Kosior¹,², Elfar Adalsteinsson⁴,⁵, Lawrence L. Wald²,⁵

¹Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; ²Martinos Center for Biomedical Imaging, Dept. of Radiology, MGH, Charlestown, MA, United States; ³Martinos Center for Biomedical Imaging, Dept. of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; ⁴Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; ⁵Harvard-MIT Health Sciences and Technology, Cambridge, MA, United States

We compared the trade-off between local SAR and excitation fidelity for three 7T head transmit array configurations to determine if the approximate orthogonality between the loop coil and dipole element field patterns could be exploited for pTx. Using simulated E and B fields for 8 and 16 element loop arrays and an 8 loop + 8 dipole array, we calculated SAR constrained pTx and RF shimming pulses. Our results show that an array composed of both loop and dipole elements outperforms an array that is composed of loops only in SAR and excitation fidelity.