title: Hepatic viscoelastic parameters measured with MR elastography: correlations with quantitative analysis of liver fibrosis in the rat.
abstract: OBJECTIVE
  To determine the correlations between the viscoelastic parameters of the liver measured with in vivo MR elastography and quantitative analysis of liver fibrosis.
  
  
  METHODS
  MR elastography of the liver was performed in 10 rats with hepatic fibrosis induced by intraperitoneal carbon tetrachloride (CCl(4)) injections and five normal rats. Longitudinal waves of 200 MHz were transmitted into the liver with a mechanical transducer. Wave propagation into the liver was analyzed with a phase-locked spin-echo sequence at 1.5 T. The viscoelastic parameters, obtained with the Voigt model, were correlated with automatic image analysis of the fibrotic areas and with analysis of the hydroxyproline content of the liver.
  
  
  RESULTS
  Substantial correlations were observed between the shear viscoelastic parameters and the percentage of fibrosis at automatic image analysis (r = 0.7, P = 0.005 for the elasticity, and r = 0.8, P = 0.001 for the viscosity) and moderate correlations were seen between the shear viscoelastic parameters and the hydroxyproline content (r = 0.6, P = 0.016 for the elasticity and r = 0.5, P = 0.041 for the viscosity).
  
  
  CONCLUSIONS
  The viscoelastic parameters of the liver measured with in vivo MR elastography correlate with quantitative analysis of liver fibrosis. These results suggest that MR elastography is a promising noninvasive method to quantify liver fibrosis.
authors: Diagnostic Radiology Unit, Université Catholique de Louvain, Brussels, Belgium. najat.salameh@rdgm.ucl.ac.be
authors: Najat
authors: N
authors: Salameh
authors: Frank
authors: F
authors: Peeters
authors: Ralph
authors: R
authors: Sinkus
authors: Jorge
authors: J
authors: Abarca-Quinones
authors: Laurence
authors: L
authors: Annet
authors: Leon C
authors: LC
authors: Ter Beek
authors: Isabelle
authors: I
authors: Leclercq
authors: Bernard E
authors: BE
authors: Van Beers
mesh_terms: D000818:Animals; D001331:Automation; D002251:Carbon Tetrachloride / Q000494:pharmacology; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods; D005355:Fibrosis; D006909:Hydroxyproline / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008103:Liver Cirrhosis; D008107:Liver Diseases / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051381:Rats; D014783:Viscosity
chemical_list: D002251:Carbon Tetrachloride; D006909:Hydroxyproline