title: Estimation of the orientation distribution function from diffusional kurtosis imaging.
abstract: The Orientation Distribution Function (ODF) is used to describe the directionality of multimodal diffusion in regions with complex fiber architecture present in brain and other biological tissues. In this study, an approximation for the ODF of water diffusion from diffusional kurtosis imaging (DKI) is presented. DKI requires only a relatively limited number of diffusion measurements and, for the brain, b values no higher than 2500 s/mm(2). The DKI-based ODF approximation is decomposed into two components representing the Gaussian and non-Gaussian (NG) diffusion contributions, respectively. Simulations of multiple fiber configurations show that both the total and the NG-ODF are able to resolve the orientations of the component fibers, with the NG-ODF being the most sensitive to profiling the fibers' directions. Orientation maps obtained for in vivo brain imaging data demonstrate multiple fiber components in brain regions with complex anatomy. The results appear to be in agreement with known white matter architecture.
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York 10016-3240, USA. mariana.lazar@med.nyu.edu
authors.forename: Mariana
authors.initials: M
authors.lastname: Lazar
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
authors.forename: Liang
authors.initials: L
authors.lastname: Xuan
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Helpern
mesh_terms: D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology*; D003198:Computer Simulation; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016008:Statistical Distributions