Benjamin Bender1, Uwe Klose1
Recent
publications suggest a relationship between white matter fiber orientation
and T2* contrast at higher field strengths. In this study the relationship
between fiber orientation and B0 for normal and tilted head position was
examined in the whole human brain at 3T. As previously shown by Wiggins et al.
for the cingulum and corpus callosum, WM signal intensity in the whole brain
changed when the head was tilted. Blood vessels following the fiber tracts
could explain the relationship found between B0 and relaxation rate, while a
magic angle effect cannot explain the measured relationship.