Borjan Aleksandar Gagoski1, Rene Gumbrecht1,2, Michael Hamm3, Kawin Setsompop4,5, Boris Keil4,5, Joonsung Lee1, Khaldoun Makhoul4,5, Azma Mareyam4, Kyoko Fujimoto4, Thomas Witzel4,6, Ulrich Fontius7, Josef Pfeuffer3, Elfar Adalsteinsson1,6, Lawrence L. Wald4,6
1Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; 2Department of Physics, Friedrich-Alexander-University Erlangen, Erlangen, Germany; 3Siemens Healthcare, Charlestown, MA; 4A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; 5Harvard Medical School, Boston, MA, United States; 6Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States; 7Siemens Healthcare, Erlangen, Germany
Current challenges to high-field applications of parallel RF transmission (pTx) in vivo include the monitoring and management of local SAR. We developed and tested real-time RF monitoring system for MAGNETOM 7T (Siemens Healthcare, Erlangen, Germany) with an 8-channel prototype pTx system that limits local SAR based on numerical simulation of E fields and power deposition in a segmented head model, and tracks and compares RF waveforms on each channel to the expected digital pulse waveform and shuts down the scan in the event of a mismatch due to spurious sources of pTx RF errors.