title: Characterizing non-gaussian, high b-value diffusion in liver fibrosis: Stretched exponential and diffusional kurtosis modeling.
abstract: OBJECTIVE
  To employ the stretched exponential and diffusional kurtosis models to study the non-Gaussian behavior of diffusion-related signal decay of the liver in an animal model of hepatic fibrosis.
  
  
  METHODS
  High b-value diffusion imaging data (up to 3500 s/mm(2) ) of ex vivo murine liver specimens was acquired using a 9.4 T MRI scanner. A simple monoexponential model as well as the stretched exponential and diffusional kurtosis models were employed to analyze the diffusion data, the results of which were correlated with liver histopathology.
  
  
  RESULTS
  Strong correlations between histopathological assessments of hepatic fibrosis and parameters derived from the stretched exponential and diffusional kurtosis models were found. Using Akaike's Information Criterion (AIC) analyses, the kurtosis model was found to result in an improved fit of the high b-value diffusion data when compared to both the monoexponential and stretched exponential models.
  
  
  CONCLUSIONS
  The use of diffusional kurtosis or stretched exponential models, applied to the characterization of the non-Gaussian behavior of the molecular diffusion of liver exhibited over an extended b-factor range, affords the potential for an increased capability of magnetic resonance imaging (MRI) in the characterization of chronic liver disease.
authors.affiliation: Boston University Medical Center, Department of Radiology, Boston, Massachusetts, USA.
authors.forename: Stephan W
authors.initials: SW
authors.lastname: Anderson
authors.forename: Brian
authors.initials: B
authors.lastname: Barry
authors.forename: Jorge
authors.initials: J
authors.lastname: Soto
authors.forename: Al
authors.initials: A
authors.lastname: Ozonoff
authors.forename: Michael
authors.initials: M
authors.lastname: O'Brien
authors.forename: Hernan
authors.initials: H
authors.lastname: Jara
mesh_terms: D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D015233:Models, Statistical; D016011:Normal Distribution; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: fibrosis; kurtosis; liver; mouse; stretched exponential