Graham Wiggins1, Chris Wiggins2, Bei Zhang1, Ryan Brown1, Bernd Stoeckel3, Daniel K. Sodickson1
1Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY10016, USA; 2CEA/NeuroSpin, Saclay, France; 3Siemens Medical Solutions USA Inc, New York, NY, USA
At 7T, T2* weighted gradient echo imaging reveals unexpected contrast variation in white matter which appears to be associated with specific fiber bundles. The mechanism behind this variation has been debated, and it has been proposed that it may be caused by intrinsic properties of the fiber bundle such as degree of myelination or iron content, or that it depends on the orientation of the fiber bundles in relation to the main B0 field. With a novel coil system we obtain T2* maps in orientations 90 degrees apart and demonstrate that T2* depends strongly on orientation.