Benedikt A. Poser1,
Benjamin Zahneisen1, Robert James Anderson1, Markus
Barth2, 3, Victor Andrew Stenger1
1John
A Burns School of Medicine, University of Hawaii, Honolulu, HI, United
States; 2Donders Institute for Brain, Cognition and Behaviour,
Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, Netherlands;
3Erwin L Hahn Institute for Magnetic Resonance Imaging, University
Essen-Duisburg, Essen, Germany
Signal loss in GE-EPI is a problem that compromises the detection of BOLD activation near the air cavities, e.g. in frontal cortex and around the ear canals. The Interleaved Dual-Echo Acquisition(IDEA EPI) sequence that was recently proposed as a solution to Nyquist ghosting, is modified by incorporating a z-shim. With this we present a novel and effective method that (a) allows through-plane gradient compensation in a single shot, (b) is compatible with high-resolution fMRI and (c) remains insensitive to N/2 ghosting. The approach is evaluated using in vivo scans and breathold fMRI at 1.5x.1.5mm2 resolution; signal voids are drastically reduced.