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Abstract #3608

Multi-Echo EPI with Parallel Transmission Z-Shimming for Increased Sensitivity in BOLD fMRI

Benedikt A. Poser1, Cungeng Yang1, Weiran Deng1, Vijayanand Alagappan2,3, Lawrence L. Wald2,4, V. Andrew Stenger1

1University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; 2A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 3Department of Biomedical Engineering, Tufts University, Medford, MA, United States; 4Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, United States

Signal loss remains the most obdurate problem in gradient-echo BOLD fMRI. Here we address the issue by merging two highly promising techniques, parallel-transmission z-shimming and multi-echo EPI acquisition. ME-EPI has previously been shown to increase BOLD sensitivity over the entire brain; however it does not actively compensate for through-plane dephasing. This makes multi-channel transmission for the application of local corrective z-shims is highly complementary. The combined method is found to be more effective in reducing susceptibility artifacts than each individual approach; In vivo experiments reveal improved sensitivity in the frontal lobe, demonstrating the methods potential for fMRI application.