Andreas Schfer1, Christopher J. Wiggins2,3, Robert Turner1
1Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2CEA NeuroSpin, Gif-sur-Yvette, France; 3IFR 49, Gif-sur-Yvette, France
It was shown recently that high resolution T2*-weighted images display T2* heterogeneity in white matter and an unexpected signal dependence in the cingulum bundles on head orientation to the main magnetic field. The signal change with orientation is still poorly explained. Here we used, in addition, phase images arising from high resolution spoiled gradient echo sequences, because such images are more sensitive to susceptibility effects. We also obtained TSE images to determine whether the orientation dependence of the signal appears in that sequence as well. Furthermore we compared the measurements with simulations using the forward field calculation.