title: More accurate estimation of diffusion tensor parameters using diffusion Kurtosis imaging.
abstract: With diffusion tensor imaging, the diffusion of water molecules through brain structures is quantified by parameters, which are estimated assuming monoexponential diffusion-weighted signal attenuation. The estimated diffusion parameters, however, depend on the diffusion weighting strength, the b-value, which hampers the interpretation and comparison of various diffusion tensor imaging studies. In this study, a likelihood ratio test is used to show that the diffusion kurtosis imaging model provides a more accurate parameterization of both the Gaussian and non-Gaussian diffusion component compared with diffusion tensor imaging. As a result, the diffusion kurtosis imaging model provides a b-value-independent estimation of the widely used diffusion tensor parameters as demonstrated with diffusion-weighted rat data, which was acquired with eight different b-values, uniformly distributed in a range of [0,2800 sec/mm(2)]. In addition, the diffusion parameter values are significantly increased in comparison to the values estimated with the diffusion tensor imaging model in all major rat brain structures. As incorrectly assuming additive Gaussian noise on the diffusion-weighted data will result in an overestimated degree of non-Gaussian diffusion and a b-value-dependent underestimation of diffusivity measures, a Rician noise model was used in this study.
authors.affiliation: Visionlab, Department of Physics, University of Antwerp, Wilrijk, Antwerp, Belgium. jelle.veraart@ua.ac.be
authors.forename: Jelle
authors.initials: J
authors.lastname: Veraart
authors.forename: Dirk H J
authors.initials: DH
authors.lastname: Poot
authors.forename: Wim
authors.initials: W
authors.lastname: Van Hecke
authors.forename: Ines
authors.initials: I
authors.lastname: Blockx
authors.forename: Annemie
authors.initials: A
authors.lastname: Van der Linden
authors.forename: Marleen
authors.initials: M
authors.lastname: Verhoye
authors.forename: Jan
authors.initials: J
authors.lastname: Sijbers
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity