title: Conventional DTI vs. slow and fast diffusion tensors in cat visual cortex.
abstract: Diffusion tensor imaging (DTI) uses water diffusion anisotropy in axonal fibers to provide a tool for analyzing and tracking those fibers in brain white matter. In the present work, multidirectional diffusion MRI data were collected from a cat brain and decomposed into slow and fast diffusion tensors and directly compared with conventional DTI data from the same imaging slice. The fractional anisotropy of the slow diffusing component (D(slow)) was significantly higher than the anisotropy measured by conventional DTI while reflecting a similar directionality and appeared to account for most of the anisotropy observed in gray matter, where the fiber density is notoriously low. Preliminary results of fiber tracking based on the slow diffusion component are shown. Fibers generated based on the slow diffusion component appear to follow the vertical fibers in gray matter. D(slow)TI may provide a way for increasing the sensitivity to anisotropic structures in cortical gray matter.
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA. itamar@cmrr.umn.edu
authors.forename: Itamar
authors.initials: I
authors.lastname: Ronen
authors.forename: Keun-Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Michael
authors.initials: M
authors.lastname: Garwood
authors.forename: Kamil
authors.initials: K
authors.lastname: Ugurbil
authors.forename: Dae-Shik
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000818:Animals; D016880:Anisotropy; D002415:Cats; D038524:Diffusion Magnetic Resonance Imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009412:Nerve Fibers; D014793:Visual Cortex / Q000033:anatomy & histology*