title: Liver fibrosis: non-invasive assessment with MR elastography.
abstract: The aim of this study was to assess the feasibility of using non-invasive MR elastography for determining the stage of liver fibrosis. Twenty-five consecutive patients who had liver biopsy for suspicion of chronic liver disease were included in the study. The stage of fibrosis on the biopsies was assessed according to the METAVIR scoring system from F0, no fibrosis, to F4, cirrhosis. MR elastography was performed by transmitting low-frequency (65 Hz) mechanical waves into the liver with a transducer placed at the back of the patients. The MR pulse sequence was a motion-sensitized spin-echo sequence, phase-locked to the mechanical excitation. The phase maps were processed to obtain shear elasticity and shear viscosity maps. The mean hepatic shear elasticity increased with increasing stage of fibrosis. The mean elasticity was 2.24 +/- 0.23 kPa in the 11 patients without substantial fibrosis (F0-F1 grades), 2.56 +/- 0.24 kPa in the four patients with substantial fibrosis (F2-F3) and 4.68 +/- 1.61 kPa in the 10 patients with cirrhosis (F4). The differences between groups were statistically significant (p <or= 0.05). The mean shear viscosity was significantly higher in the patients with cirrhosis (5.19 +/- 1.85 Pa x s) than in the patients without cirrhosis (2.39 +/- 0.86 Pa x s in F0-F1 and 2.27 +/- 0.38 Pa x s in F2-F3 patients). It is concluded that non-invasive MR elastography is a feasible method to assess the stage of liver fibrosis.
authors.affiliation: Diagnostic Radiology Unit, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Laurent
authors.initials: L
authors.lastname: Huwart
authors.forename: Frank
authors.initials: F
authors.lastname: Peeters
authors.forename: Ralph
authors.initials: R
authors.lastname: Sinkus
authors.forename: Laurence
authors.initials: L
authors.lastname: Annet
authors.forename: Najat
authors.initials: N
authors.lastname: Salameh
authors.forename: Leon C
authors.initials: LC
authors.lastname: ter Beek
authors.forename: Yves
authors.initials: Y
authors.lastname: Horsmans
authors.forename: Bernard E
authors.initials: BE
authors.lastname: Van Beers
mesh_terms: D000328:Adult; D004548:Elasticity; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology / Q000503:physiopathology*; D008103:Liver Cirrhosis / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010812:Physical Stimulation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013314:Stress, Mechanical; D014732:Vibration