title: Liver fibrosis: histopathologic and biochemical influences on diagnostic efficacy of hepatobiliary contrast-enhanced MR imaging in staging.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging in the staging of liver fibrosis in patients with diffuse chronic liver diseases (CLDs) and to investigate the factors that may influence the results.
  
  
  METHODS
  With the approval of the Hospital Ethics Committee and waiver of the informed consent requirement, data in 102 patients with histologically proven liver fibrosis (classified according to the METAVIR system) of various underlying causes were retrospectively analyzed. Patients underwent 3.0-T MR imaging with gadoxetic acid. The signal intensity of the liver was defined by using region of interest measurements before contrast material injection and in the hepatobiliary phase (20 minutes after contrast material administration), and relative enhancement was calculated. Univariate and multivariate regression analyses were applied to identify variables associated with relative enhancement measurements, and the performance of relative enhancement measurements in the staging of liver fibrosis was assessed by using area under the receiver operating characteristic curve (AUC) analysis.
  
  
  RESULTS
  At analysis of the relationship between enhancement measurements and histologic parameters, the relative enhancement values correlated strongly with liver fibrosis stage (r = -0.65, P < .0001) and moderately with necroinflammatory activity grades (r = -0.41, P = .002) and the presence of iron load (r = -0.21, P = .05). In multivariate analysis, only liver fibrosis stage independently influenced relative enhancement values (P < .001). The measurements performed well in the staging of liver fibrosis, with an AUC of 0.81 for stages of F1 or greater, 0.82 for stages of F2 or greater, 0.85 for stages of F3 or greater, and 0.83 for stage F4. Increased aspartate aminotransferase, gammaglutamyl transpeptidase, and alkaline phosphatase levels were independent predictors of false-negative results.
  
  
  CONCLUSIONS
  The presence of hepatic fibrosis can be assessed with good discrimination by using gadoxetic acid-enhanced MR imaging, but assessment can be confounded in the setting of abnormal aspartate aminotransferase, gammaglutamyl transpeptidase, and alkaline phosphatase levels.
authors.affiliation: Department of Medical Imaging, Regional Institute of Gastroenterology and Hepatology, Cluj-Napoca, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Diana
authors.initials: D
authors.lastname: Feier
authors.forename: Csilla
authors.initials: C
authors.lastname: Balassy
authors.forename: Nina
authors.initials: N
authors.lastname: Bastati
authors.forename: Judith
authors.initials: J
authors.lastname: Stift
authors.forename: Radu
authors.initials: R
authors.lastname: Badea
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ba-Ssalamah
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000473:pathology; D008111:Liver Function Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA