Leeor Alon1, Cem Murat Deniz1, Jian Xu2,3, Ryan Brown1, Daniel K. Sodickson1, Yudong Zhu1
1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States; 2Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; 3Siemens Medical Solutions, Malvern, PA, United States
In this work, we present a custom automated pulse sequence that volumetrically maps local SAR for parallel transmit systems with minimal manual intervention. This sequence combines MR thermometry and RF heating to determine the local electric field covariance matrix〖 Λ〗_r and thereby to calibrate a robust local SAR model. Once the model is calibrated, SAR maps specific to the particular geometry of the coil array and content of the imaged body can be obtained for any pulse shape/RF shimming combination. This sequence is particularly useful for assessing local SAR in phantoms for parallel transmission arrays and matching results with simulations.