Carsten Stueber1, Markus Morawski2, Katja Reimann1, Nirav Barapatre3, Stefan Geyer1, Robert Turner1
1Department of Neurophysics, Max-Planck-Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; 2Paul-Flechsig-Institute of Brain Research, University of Leipzig, Germany; 3LIPSION Laboratory, Institute of Nuclear Solid State Physics, University of Leipzig, Germany
MR imaging at ultra-high field strengths has tremendously improved the visualization of human brain structures in recent years. In particular, strong differences in contrast are seen within the cerebral cortex that apparently reflect local myeloarchitecture. There is an ongoing controversy regarding the relative importance of iron in myelinated tissue, as a partly independent source of tissue contrast. We used a new powerful technique, the so-called Proton-Induced X-Ray Emission (PIXE), which provides a gold standard for mapping the intracortical iron content and could show that conventional staining methods do not adequately reflect the true iron distribution.