Hepatic viscoelastic parameters measured with MR elastography: correlations with quantitative analysis of liver fibrosis in the rat.
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.
Salameh
Najat
N
Diagnostic Radiology Unit, Université Catholique de Louvain, Brussels, Belgium. najat.salameh@rdgm.ucl.ac.be
Peeters
Frank
F
Sinkus
Ralph
R
Abarca-Quinones
Jorge
J
Annet
Laurence
L
Ter Beek
Leon C
LC
Leclercq
Isabelle
I
Van Beers
Bernard E
BE
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
D002251:Carbon Tetrachloride; D006909:Hydroxyproline