title: Computational modeling of MR flow imaging by the lattice Boltzmann method and Bloch equation.
abstract: In this work, a computational model of magnetic resonance (MR) flow imaging is proposed. The first model component provides fluid dynamics maps by applying the lattice Boltzmann method. The second one uses the flow maps and couples MR imaging (MRI) modeling with a new magnetization transport algorithm based on the Eulerian coordinate approach. MRI modeling is based on the discrete time solution of the Bloch equation by analytical local magnetization transformations (exponential scaling and rotations). Model is validated by comparison of experimental and simulated MR images in two three-dimensional geometries (straight and U-bend tubes) with steady flow under comparable conditions. Two-dimensional geometries, presented in literature, were also tested. In both cases, a good agreement is observed. Quantitative analysis shows in detail the model accuracy. Computational time is noticeably lower to prior works. These results demonstrate that the discrete time solution of Bloch equation coupled with the new magnetization transport algorithm naturally incorporates flow influence in MRI modeling. As a result, in the proposed model, no additional mechanism (unlike in prior works) is needed to consider flow artifacts, which implies its easy extensibility. In combination with its low computational complexity and efficient implementation, the model could have a potential application in study of flow disturbances (in MRI) in various conditions and in different geometries.
authors.affiliation: Faculty of Computer Science, Bialystok University of Technology, Wiejska 45a, 15-351 Bialystok, Poland. k.jurczuk@pb.edu.pl
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Jurczuk
authors.forename: Marek
authors.initials: M
authors.lastname: Kretowski
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Bellanger
authors.forename: Pierre-Antoine
authors.initials: PA
authors.lastname: Eliat
authors.forename: Hervé
authors.initials: H
authors.lastname: Saint-Jalmes
authors.forename: Johanne
authors.initials: J
authors.lastname: Bézy-Wendling
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity; D003198:Computer Simulation; D060733:Electromagnetic Radiation; D006801:Humans; D057446:Hydrodynamics; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D011673:Pulsatile Flow; D013997:Time Factors
keywords: Bloch equation; Computer modeling and simulation; Fluid flow; Lattice Boltzmann method (LBM); Magnetic resonance imaging (MRI)