Antoine Lutti1, Chloe Hutton1,
Jorg Stadler2, Oliver Josephs1, Oliver Speck3,
Claus Tempelmann4, Johannes Bernarding5, Nikolaus
Weiskopf1
1Wellcome Trust Centre for
Neuroimaging, Institute of Neurology, University College London, London,
United Kingdom; 2Special Lab Non-Invasive Brain Imaging, Leibniz
Institute for Neurobiology, Magdeburg, Germany; 3Dept. Biomedical
Magnetic Resonance, Institute for Experimental Physics , Otto-von-Guericke
University, Magdeburg, Germany; 4Department of Neurology,
Otto-von-Guericke University, Magdeburg, Germany; 5Institute for
Biometry and Medical Informatics, Faculty of Medicine,
Otto-von-Guericke-University, Magdeburg, Germany
Spatial
inhomogeneities in the radio-frequency (RF) field (B1) increase with field
strength affecting quantification and image contrast. Fast and robust
whole-brain B1 mapping methods are therefore essential to correct for B1
inhomogeneities at ultra-high fields. Here we optimize a SE/STE 3D EPI method
for rapid B1 mapping at 7T, addressing severe off resonance effects and
reducing sensitivity to transverse coherence effects. We demonstrate the
robustness of this B1 mapping technique and illustrate its accuracy by
correcting for B1 inhomogeneities in T1 maps.
Keywords