title: Generalization of intravoxel incoherent motion model by introducing the notion of continuous pseudodiffusion variable.
abstract: A generalized intravoxel incoherent motion (IVIM) model, called the GIVIM, was proposed to better account for complex perfusion present in the tissues having various vessels and flow regimes, such as the liver.
  
  
  
  The notions of continuous pseudodiffusion variable as well as perfusion fraction density function were introduced to describe the presence of multiple perfusion components in a voxel. The mean and standard deviation of Gaussian perfusion fraction density function were then used to define two new parameters, the mean pseudodiffusivity ( D¯) and pseudodiffusion dispersion (σ). The GIVIM model was evaluated by testing whether or not it can reflect hepatic perfusion difference caused by flow-compensated imaging sequences having different diffusion times. Also, D¯ was compared with D* in the standard IVIM model.
  
  
  
  The values of both D* and D¯ decreased after flow compensation and further decreased when shortening diffusion time. D¯ exhibited reduced variance in comparison with D*. In addition, σ also showed its sensitivity to hepatic perfusion difference caused by the flow-compensated imaging sequences.
  
  
  
  The GIVIM model has the ability to better describe multicomponent perfusion without lengthening acquisition time and knowing in advance the number and/or the variety of perfusion components. Magn Reson Med 76:1594-1603, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
authors.affiliation: International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT), Harbin, China.|CREATIS, CNRS (UMR 5220); INSERM (U1044); INSA Lyon; Universite de Lyon, Villeurbanne, France.
authors.forename: Zi-Xiang
authors.initials: ZX
authors.lastname: Kuai
authors.affiliation: International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT), Harbin, China. liu_wanyu@hit.edu.cn.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Liu
authors.affiliation: International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT), Harbin, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Zhang
authors.affiliation: International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT), Harbin, China.|CREATIS, CNRS (UMR 5220); INSERM (U1044); INSA Lyon; Universite de Lyon, Villeurbanne, France.
authors.forename: Yue-Min
authors.initials: YM
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000502:physiology*; D008102:Liver Circulation / Q000502:physiology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: IVIM; continuous pseudodiffusion variable; diffusion-weighted imaging; flow compensation; liver; multiple perfusion components