Chunlei Liu1,2
1Brain Imaging and Analysis Center,
Duke University, Durham, NC, United States; 2Radiology, Duke
University, Durham, NC, United States
We
propose a susceptibility tensor imaging (STI) technique to measure and quantify
anisotropy of magnetic susceptibility. This technique relies on the
measurement of resonance frequency offset at different orientations. We
propose to characterize the orientation variation of susceptibility using an
apparent susceptibility tensor. The susceptibility tensor can be decomposed
into three eigenvalues (principle susceptibilities) and associated
eigenvectors that are coordinate-system independent. We show that the
principle susceptibilities offer strong contrast between gray and white matter
while the eigenvectors provide orientation information of an underlying
magnetic network. We believe that this network may further offer information
of white matter fiber orientation.