title: Diffusion analysis with triexponential function in liver cirrhosis.
abstract: OBJECTIVE
  To acquire more detailed information noninvasively through on diffusion and perfusion in normal and cirrhotic livers, we analyzed three diffusion components using triexponential function.
  
  
  METHODS
  Thirty-nine subjects (10 with noncirrhotic liver, 29 with cirrhosis) were assessed using diffusion-weighted magnetic resonance imaging (DWI) with multiple b-values. We derived perfusion-related diffusion, fast free diffusion, and slow restricted diffusion coefficients (Dp , Df , Ds ) and fractions (Fp , Ff , Fs ) calculated from triexponential function using DWI data. Moreover, the triexponential analysis was compared with biexponential and monoexponential analyses. All derived diffusion coefficients were correlated with relative enhancement ratio (RER) using dynamic contrast-enhanced MRI.
  
  
  RESULTS
  In triexponential analysis, Fp , Dp , and Ds were significantly reduced in cirrhosis, whereas Ff was significantly increased in cirrhosis. There was no correlation between each diffusion coefficient obtained with the triexponential analysis in both groups, i.e., Dp , Df , and Ds , did not necessarily provide the same kind of information, but there was a positive correlation between each diffusion coefficient with the biexponential analysis in cirrhosis. A positive correlation was found between Dp and RER in the portal phase.
  
  
  CONCLUSIONS
  Triexponential analysis makes it possible to noninvasively obtain more detailed tissue diffusion and perfusion information and to assist in the diagnosis of liver cirrhosis.
authors.affiliation: Department of Radiological Technology, Toranomon Hospital, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hayashi
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.forename: Junji
authors.initials: J
authors.lastname: Takahashi
authors.forename: Kei
authors.initials: K
authors.lastname: Fukuzawa
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sakai
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Tano
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saitoh
mesh_terms: D000328:Adult; D000465:Algorithms; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult