Sebastian Schmitter1, Xiaoping Wu1, Edward J. Auerbach1, Michael Hamm2, Josef Pfeuffer3, Kamil Ugurbil1, Pierre-Francois Van De Moortele1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Siemens Healthcare, Charlestown, MA, United States; 3MR Application Development, Siemens Healthcare, Erlangen, Germany
One of the main challenges in ultra-high-field imaging is the spatial inhomogeneity of transmit B1. In cerebral time-of-flight (TOF) angiography this inhomogeneity results in spatially varying background suppression and thus suboptimal contrast. Parallel transmission (pTX) proved to generate homogeneous excitation by using independent RF waveforms on multiple transmit channels. So far, however, pTX methods have not been used at a large scale in clinical applications, and it remains to be demonstrated that this approach provides reliable results in clinical MR protocols. In this report we demonstrate the successful implementation of Spoke 3D RF pulses in multi-slab TOF angiography at 7T.