Florent Eggenschwiler1, Arthur Magill1,2, Rolf Gruetter1,3, Jos P. Marques1,2
1EPFL, Laboratory for Functional and Metabolic Imaging, Lausanne, Vaud, Switzerland; 2University of Lausanne, Department of Radiology, Lausanne, Vaud, Switzerland; 3Universities of Geneva and Lausanne, Department of Radiology, Switzerland
Sa2RAGE is based on the rapid acquisition of two images with low flip angles just before and after a saturation pulse. The ratio of the signals from the images can be linked to a specific B1+. Optimization of the sequence parameters allowed the derivation of a protocol that performs 3D B1+-mapping in ~30s (matrix size 64x64x16) with limited T1 dependence. Experimental work showed the accuracy of the B1+-mapping over a 10 fold range of B1+. In-vitro and in-vivo B1+ maps were performed to demonstrate the applicability of the method on the context of parallel transmission.