title: 3D fiber tractography with susceptibility tensor imaging.
abstract: Gradient-echo MRI has revealed anisotropic magnetic susceptibility in the brain white matter. This magnetic susceptibility anisotropy can be measured and characterized with susceptibility tensor imaging (STI). In this study, a method of fiber tractography based on STI is proposed and demonstrated in the mouse brain. STI experiments of perfusion-fixed mouse brains were conducted at 7.0T. The magnetic susceptibility tensor was calculated for each voxel with regularization and decomposed into its eigensystem. The major eigenvector is found to be aligned with the underlying fiber orientation. Following the orientation of the major eigenvector, we are able to map distinctive fiber pathways in 3D. As a comparison, diffusion tensor imaging (DTI) and DTI fiber tractography were also conducted on the same specimens. The relationship between STI and DTI fiber tracts was explored with similarities and differences identified. It is anticipated that the proposed method of STI tractography may provide a new way to study white matter fiber architecture. As STI tractography is based on physical principles that are fundamentally different from DTI, it may also be valuable for the ongoing validation of DTI tractography.
authors.affiliation: Brain Imaging and Analysis Center, School of Medicine, Duke University, 2424 Erwin Rod, Suite 501, Durham, NC 27705, USA. chunlei.liu@duke.edu
authors.forename: Chunlei
authors.initials: C
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Wu
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang
authors.forename: G Allan
authors.initials: GA
authors.lastname: Johnson
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000166:cytology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity