title: Simulation and experimental verification of the diffusion in an anisotropic fiber phantom.
abstract: Diffusion weighted magnetic resonance imaging enables the visualization of fibrous tissues such as brain white matter. The validation of this non-invasive technique requires phantoms with a well-known structure and diffusion behavior. This paper presents anisotropic diffusion phantoms consisting of parallel fibers. The diffusion properties of the fiber phantoms are measured using diffusion weighted magnetic resonance imaging and bulk NMR measurements. To enable quantitative evaluation of the measurements, the diffusion in the interstitial space between fibers is modeled using Monte Carlo simulations of random walkers. The time-dependent apparent diffusion coefficient and kurtosis, quantifying the deviation from a Gaussian diffusion profile, are simulated in 3D geometries of parallel fibers with varying packing geometries and packing densities. The simulated diffusion coefficients are compared to the theory of diffusion in porous media, showing a good agreement. Based on the correspondence between simulations and experimental measurements, the fiber phantoms are shown to be useful for the quantitative validation of diffusion imaging on clinical MRI-scanners.
authors.affiliation: Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185, Ghent, Belgium. Els.Fieremans@ugent.be
authors.forename: Els
authors.initials: E
authors.lastname: Fieremans
authors.forename: Yves
authors.initials: Y
authors.lastname: De Deene
authors.forename: Steven
authors.initials: S
authors.lastname: Delputte
authors.forename: Mahir S
authors.initials: MS
authors.lastname: Ozdemir
authors.forename: Yves
authors.initials: Y
authors.lastname: D'Asseler
authors.forename: Jelle
authors.initials: J
authors.lastname: Vlassenbroeck
authors.forename: Karel
authors.initials: K
authors.lastname: Deblaere
authors.forename: Eric
authors.initials: E
authors.lastname: Achten
authors.forename: Ignace
authors.initials: I
authors.lastname: Lemahieu
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D001834:Body Water / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods*; D003198:Computer Simulation; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D009010:Monte Carlo Method; D009412:Nerve Fibers; D019047:Phantoms, Imaging